MSL925003: Uncertainty Measurement in Bitumen Extraction Analysis

This practical assignment, MSL925003, assesses the student's ability to determine and quantify uncertainty in asphalt testing procedures. The assignment focuses on two primary tasks: calculating the uncertainty in finding the percentage of bitumen in an asphalt sample using the bitumen extraction method, and determining the uncertainty associated with Marshall density and air voids in an asphalt sample. The student is guided through the ISO GUM method, requiring them to identify sources of uncertainty, quantify these uncertainties using provided data from calibration certificates and product specifications, and calculate both combined standard uncertainty and expanded uncertainty. The tasks involve detailed calculations and the application of statistical methods to evaluate the precision of measurements. The student must describe the measurand, identify uncertainty sources, quantify uncertainties, calculate combined standard uncertainty, calculate expanded uncertainty, and report the uncertainty findings. Workplace evidence can be submitted, and knowledge questions must be answered. The assignment emphasizes the importance of accurate measurements and the quantification of error in materials testing, crucial for quality control and assurance in civil engineering applications.

Complete
Assessment
MSL925003 Determine measurements of uncertainty
Name of Student: ___________________________________________________
Workplace: ___________________________________________________

MSL925003 Determine measurements of uncertainty
Important Information for the Student
1. This document contains two (2) assessment methods used to determine competency
for the unit. They include practical tasks and knowledge questions.
2. Some practical tasks do not need to be completed if sufficient workplace evidence
is submitted that covers the required performance evidence. Check with your
assessor if you believe you have relevant evidence.
3. To achieve a satisfactory result in this assessment, all parts of this document must
be filled in by either answering the question, performing the task or providing
workplace evidence.
4. If workplace evidence is submitted, the assessment sections must still be filled in
with references made to the evidence collected. Name and number the evidence
document for tracking.
5. Knowledge questions must always be completed and cannot be replaced with
workplace evidence.
6. If completing on hardcopy, you must use black pen only. Whiteout, pencils or other
coloured pens are not acceptable.
7. A degree of independent research utilising current and reliable sources may also be
required to complete the assessment.
8. Please ensure you keep a copy of your assessment for you own records. If your
assessment is lost, it is your responsibility to provide a copy or reproduce your
work as required to demonstrate satisfactory practical knowledge.
9. The outcome of each practical task or knowledge question is either Satisfactory (S)
or Not Yet Satisfactory (NYS).
10. You will be given three (3) attempts to complete each practical task and knowledge
question. This means if you are deemed NYS on your first attempt, you will be
given the opportunity to resubmit the answer or perform the task twice more only.
11. Please note that this is an ‘open book’ assessment. The Study Guide for this unit
may be used to assist you.
12. You are required to sign at the completion of each assessment method.
Assessment:
The practical tasks for this unit comprise a combination of assessment tasks including:
 Determine the uncertainty in finding the percentage bitumen in asphalt via a
bitumen extraction
Complete Assessment v1.0 March 2020 Page 2

MSL925003 Determine measurements of uncertainty
 Determine the uncertainty in finding the Marshall Density and air voids in an
asphalt sample
 Determine uncertainty of linearity
 Determine uncertainty of percentage void filled bitumen of an asphalt sample
Complete Assessment v1.0 March 2020 Page 3

MSL925003 Determine measurements of uncertainty
Practical Assessment
Important Information for the Student
If you believe you have completed a similar task in your workplace you have the option to
submit the workplace evidence to your assessor for consideration. Please speak to your
assessor for further information.
Practical Task 1: Determine the uncertainty in finding the percentage bitumen in asphalt
via a bitumen extraction
Description:
Read the following test data to calculate the uncertainty as per the ISO GUM method.
Test data:
1296.62 g of an asphalt sample is analysed for bitumen content by carrying out a bitumen
extraction according to standard test methods, with all drying carried out at 105°C.
Lab temperature on the day of preparation of solution is noted as 24°C.
The following documents are provided to you:
 CPA1 – Test sheet – Bitumen extraction - BE5003-1
 CPA2 – Product description – Measuring cylinder 2 L
 CPA3 – Calibration certificate – Analytical balance – AB5003-1
 CPA4 – Product description – Measuring cylinder 100 mL
 CPA5 – Product specification – Oven – TO5003-1
Instructions:
Follow the six (6) steps to calculate and report the combined standard uncertainty and expanded
uncertainty.
Show your calculations below.
Step 1: Describe the measurand
The main aim of this process is to establish the percentage of bitumen in 1296.62g of asphalt
sample. The percentage bitumen is determined by the bitumen extraction method.
Lab temperature during this experiment was 24 oC.
Drying in this experiment was carried out at a temperature of 105 oC.
Apparatus
 Extraction apparatus
 Analytical balance
 Suitable solvent
 Filter rings
 Centrifuge
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MSL925003 Determine measurements of uncertainty
 Centrifuge tubes
 Measuring cylinders
 Oven
Procedure;
 Using the analytical balance accurately weigh 1296.62 g of the asphalt sample (m1).
Dry the (m1) at a controlled temperature of 105oC to obtain a constant mass of 1226.69 g (m2)
Mass of the filter ring was 19.87 g(m3)
Mass after extraction was 1226.69 g (m4)
Weights recorded by analytical balance are to the nearest 0.01g.
 Mass of the filter ring and residue measured was found to be 20.49 g (m5)
 Mass of residue (on filter ring) (m6) = (m5-m3) = 0.62 g
 Total mass of the centrifuge tubes (m7) = 179.02 g
 Mass of residue and tubes (m8) = 179.56 g
 Total mass of residue in tubes(m9) = (179.56-179.02) g = 0.54 g
 Total volume of solvent was 1460ml
 Volume of aliquot was 81ml
 Mass of fines in fluid (m10) = (m9*(1460/81)) = 9.73 g
 Total mineral matter(m11) (m2+m6+m10) = 1236.97 g
 Weight of bitumen(m12) (m1-m11) g = 59.65 g
 % bitumen (m12/m1) = 4.6%
Step 2: Identify sources of uncertainty
Step 3: Quantify uncertainty
Balance: The bitumen determination begins with weighing the asphalt sample using the
analytical balance.
Complete Assessment v1.0 March 2020 Page 5
solvent
Standard
flask
Weighing
balance
repeatability
Sensitivity
% bitumen in asphalt
sample
calibration
Oven
calibration temperature
Control
accuracy

MSL925003 Determine measurements of uncertainty
The following information are obtained from the calibration certificate:
Repeatability = 0.01g from 10 trials
Sensitity offset = 0.10g
Linerity deviation = 0.04g
Repeatability checks are conducted in the calibration of the analytical balance as per the NATA
technical note. This therefore is a type A evaluation.the repeaterbility checks follows a normal
distributuion. Standard deviation is associated with the analytical balace.
Standard uncertainity = standard deviation(type A) obtained from quality control data
Total uncertainity of balance is calculated using RSS
Ubalance = (0.012 + 0.12 + 0.042 )1/2
Ubalance = 0.108167 g
Standard flask (100ML )
Calibrattion uncertainity is 1ml. Assume triangular distribution.
Standard uncertainity of calibration of sf = (1/61/2) = 0.4082ml
Standard uncertainity of repeatability of sf = 0.2 ml
Temprature: bitumen extraction was done at 24oc but standard flask was calibrated at 20 oC
Coefficient of volume expansion of solvent = 2.1*10-4 oC
Volume variation = 100*10*2.1*10-4 = 0.21 ml
For a rectangular distribution = 0.21/1.73 = 0.12138 ml
Standard unceratinity for flask = Usf = (0.22 + 0.00982 + 0.40822)
Uncertainity of standard flask – 100ml
Component Uncertainity Type Distribution Standard
uncertainity
Square
Repeaterbilit
y
0.2 A Normal 0.2 0.04
Complete Assessment v1.0 March 2020 Page 6
Uncertainity of balance
Componen
t
Uncertainit
y
Type Distributio
n
Standard uncertainity Square
Repeatabili
ty
0.01 A Normal 0.01 0.0001
Sensitivity 0.1 A Normal 0.1 0.01
Linearity 0.04 A Norrml 0.04 0.0016
Sum 0.0117
Square root 0.108167

MSL925003 Determine measurements of uncertainty
Temperature 0.21 B resctangular 0.12138 0.01473
Accuracy 1 B triangular 0.4082 0.16663
sum 0.221363
Square root 0.4705
Usf = 0.4705
Standard flask 2000ml
Calibration uncertaunity is 10 ml .assume triangular distribution
Standard uncertainity of calibration of sf =(10/61/2) = 4.0825 ml
Standard uncertainity of sf = 3 ml
Temperature: standard flask was calibrated at 20oc but bitumen extraction was done at 24 oC
Coefficient of volume expansion of water = 2.1 * 10-4 oC
Volume variation = 2000 * 0.5 * 2.1 * 10-4 oC = 0.21 ml
Assuming rectangular distribution 0.21/1.73 = 0.12138 ml
Standard uncertainity for flask = Usf = (4.08252 + 32 + 0.121382 )1/2
Uncertainity of standard flask – 2000ml
Component Uncertainity Type Distribution Standard
uncertainity
Square
Repeaterbilit
y
3 A Normal 3 9
Temperature 0.21 B Resctangular 0.12138 0.01473
Accuracy 10 B triangular 4.0825 16.6668
Sum 25.68154
Square root 5.0677
Usf= 5.0677
oven: all drying in this experiment were carried out at a controlled temperature of 105 oC.
the following information are true for this product
temerature range: 10-200 oC
control accuracy ± 0.25 oC
temperature uniformity ± 2oC
the moisture mass fraction wH2O, expresssed as g g-1 is the mass of water evaporated during the
sdample drying at 105oc to constant mass of 1226.69 g
wH2O =( m(c+s) -m( c+s) dry)/m(c+s)-mc =0.086 assuming rectangular distribution
the dry matter mass fraction wDM,, is the dry residue content obtained afyet drying the sample at
Complete Assessment v1.0 March 2020 Page 7

MSL925003 Determine measurements of uncertainty
105 oc
wDM = (m(c+s) dry –mc/m(c+s) –mc) = 0.914 assuming rectangular distribution
combined oven uncertainity = (0.914-0.086) = 0.828
significance of unceratinity componets
Description Standard uncertainity square
Mass weighed 0.108167 0.0117
Standard flask 100ml 0.4705 0.2213
Standard flask
2000ml
5.0677 25.682
Drying 0.828 0.6856
Sum 26.60
Square root
5.16
Step 4: Calculate combined standard uncertainty
Combined unsertainity is calculated as follows
Uncerat
ainity
Descript
ion
Distribu
tion
type Standar
d
uncertai
ty
Relative
uncertai
nity
Sensitiv
ity
coeffici
ent
Relative
variance
Balance Sample
mass
Normal A 0.10816
7
0.00008 1 2.606
Vsf Volume
of
solvent
Restang
ular
B 0.4705 0.00470
5
1 1.2406
Vsf Volume
of
solvent
Rectang
ular
B 5.0677 0.00253
3
1 1.404
Oven Drying Restang
ular
B 0.828 0.00788 1 2.3404
sum 7.591
Square
root
2.755
Uncertainity is 2.755
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MSL925003 Determine measurements of uncertainty
Step 5: Calculate expanded uncertainty
Degree of freedom for type B uncertainty are assumed to be infinite since they constitute most
of the uncertainty components. Degree of freedom are only calculated for uncertainty
component of type A. since there were 10 trials conducted in weighing,
Degree of freedom = n-1
= 10-1 =9
Uncertainty is reported at 95% confidence level
The coverage factor at this point is 2.262
Expanded uncertainty = 2.262 * 2.755
6.23%.
Step 6: Report uncertainty
Reporting combined standard uncertainty
The percentage of bitumen in asphalt sample is 4.6% with a combined standard uncertainty of
2.75%
Reporting expanded uncertainty
The percentage of bitumen in 1296.g of asphalt sample is 4.6 % with a coverage factor of 2.26,
the expanded uncertainty is 6.23%. Degree of freedom is 9 estimated to have a confidence of
95%.
Practical Task 2: Determine the uncertainty in finding the Marshall Density and air
voids in an asphalt sample
Description:
Read the following test data to calculate the uncertainty as per the ISO GUM method.
Test data:
A sample from the same bulk material as task 1 was analysed for its Marshall density and
the voids filled with bitumen (VFB) were calculated.
Lab temperature at the time analysis is noted as 23 °C.
The following documents are provided to you:
 CPA6- Marshall density and air voids test sheet – MDAV5003-1
 CPA7- Product description – Ruler 30 cm
 CPA3 - Product description – Analytical balance – AB5003-1
Complete Assessment v1.0 March 2020 Page 9

MSL925003 Determine measurements of uncertainty
Instructions:
Follow the six (6) steps as per the ISO GUM method to calculate and report the combined
standard uncertainty and expanded uncertainty.
Show your calculations below.
Step 1: Describe the measurand
The aim of this experiment is to determine the void filled with bitumen and the Marshall
density of the asphalt sample. The apparatus to be used in this analysis include;
a. Analytical balance. This was used in obtaining the accurate mass of 1226.62 g of
the asphalt sample.
b. 30 cm ruler of measuring range of 0-300mm. This was used in measuring the
height of the sample and diameter of the sample.
The lab temperature at the time analysis was 23oC
Procedure
Using the analytical balance accurately weigh 1226.62 g of the asphalt sample (m1)
The diameter of the sample was measured using the ruler and was found to be 10l.06 mm
(d)
The height of the sample was 63.00mm(h)
Volume of the sample was calculate using the following formula (пd2h/4000) cm3
Volume of sample (v) = 505.3462166cm3
Bulk density (d1) = (m1/v)
= (1226.62 /505.3462166) g/cm3
= 2.4272 g/cm3
Maximum density(d2) = 2.496 g/cm3
% Air voids (g) = (d2-d1)/d2) * 100 = 2.7529486%
% bitumen(h) = 4.6% with a combined standard uncertainty of 0.014%
Density of bitumen(h1) = 1.04
% vol bitumen(j)= (d1*h)/h1 = 10.5335 %
Total void aggregate (g+j) = 13.2864%
% VFB (k) = 79.28%
Step 2: Identify sources of uncertainty
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linearity Weighing
balance
repeatability
Sensitivity

MSL925003 Determine measurements of uncertainty
Step 3: Quantify uncertainty
Balance: the first step in the analysis of the marshall density and the percentage VFB
begins with weighing the asphalt sample using the analytical balance.
The following information are obtained from the calibration certificate:
Repeatability = 0.01g from 10 trials
Sensitity offset = 0.10g
Linerity deviation = 0.04g
Repeatability checks are conducted in the calibration of the analytical balance as per the
NATA technical note. This therefore is a type A evaluation.the repeaterbility checks
follows a normal distributuion. Standard deviation is associated with the analytical balace.
Standard uncertainity = standard deviation(type A) obtained from quality control data
Total uncertainity of balance is calculated using RSS
Ubalance = (0.012 + 0.12 + 0.042 )1/2
Ubalance = 0.108167 g
30cm ruler; the following information is obtained from the product description sheet
Measuring range 0-300 mm
Unceratinity ± 1mm
Complete Assessment v1.0 March 2020 Page 11
% VFB
calibration
30 cm ruler
calibration temperature
Control
accuracy
Uncertainity of balance
Componen
t
Uncertainit
y
Type Distributio
n
Standard uncertainity square
Repeatabili
ty
0.01 A Normal 0.01 0.0001
Sensitivity 0.1 A Normal 0.1 0.01
Linearity 0.04 A Norrml 0.04 0.0016
Sum 0.0117
Square root 0.108167

MSL925003 Determine measurements of uncertainty
The coefficeint of thermal expansion = 17.3*10-6 oC
Calibration temperature 20oC
Measuremernts made
Height of sample 63.00 ± 1 mm
Diameter of sample 101.06 ± 1mm
Combine uncertainity of measurement = ( ±1/2)= ± 0.5 mm
Temperature: temperature during analysis was 23oc while that of calibration was 20oC.
Temperature variation = 30 *3*17.3*10-6 oC*10 = 0.0153 mm assuming resctangular
distribution.
Standard uncertainity for the 30cm ruler = (0.0153)1/2 = 0.1234 mm
Step 4: Calculate combined standard uncertainty
Uncertainity in determing %VFB and marshall density
uncer
tainit
y
descriptio
n
distributio
n
Type Standard
uncertainit
y
Relative
uncertainit
y
Relative
variance
balan
ce
mass Normal A 0.108167 0.0000834 0.01811
30cm
ruler
dimension
s
Rectangul
ar
B 0.1234 0.00196 0.1588
Sum 0.17691
Square
root
0.4206
Combined stanadard uncertainity = 0.4206
Step 5: Calculate expanded uncertainty
Expanded uncertainty is calculated based on degrees of freedom. Degree of freedom is
only given for uncertainty type A. mass measurements using the balance was done in 10
trials.
Degree of freedom = n-l
= 10-1= 9
Uncertainty is reported at 95% confidence level.
From the student t table coverage factor is 2.262 at 95% confidence level
Expanded uncertainty= 2.262*0.4206 = 0.9514%
Step 6: Report uncertainty
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MSL925003 Determine measurements of uncertainty
Reporting combined standard uncertainty
%VFB is 79.28 with combined uncertainty of 0.4206
Reporting expanded uncertainty
The percentage VFB is reported as 79.28% ± 0.9514% with a coverage factor of 2.262 on 9
degrees of freedom and estimated to have a confidence of 95%.
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MSL925003 Determine measurements of uncertainty
Practical Task 3: Determine uncertainty of linearity
Description of the Task:
You are required to determine the uncertainty of linearity using the data from CPA16 -
Spectrometry test sheet 5003-1.
Instructions:
 Plot a calibration graph in Microsoft Excel using the test data given in CPA16 -
Spectrometry test sheet 5003-1.
 Obtain the line of best fit
 Calculate the uncertainty of linearity (ulinearity)
 Show your calculations below.
 Provide a copy of the Excel document containing the calibration graph to your
Assessor.
Linear regression was conducted to obtain the line of best fit
Uncertainity of linearity is calculated using the following equation:
Ulinearity = Max |yobserved-yfitted|
Yobseved is obtained experimentally = 0.95
Microsoft excel was used in determining yfitted. using the equation below
y= 0.0002x -0.0046
= 0.0002(5000) – 0.0046
Yfitted = 0.9954
Ulinearity = max | 0.962 – 0.9954 |
= 0.0334
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MSL925003 Determine measurements of uncertainty
Practical Task 4: Determine uncertainty of percentage void filled bitumen of an
asphalt sample
Description:
Read the following test data from the bitumen extraction and Marshall density and air voids
testing, then calculate uncertainty as per the ISO GUM method to determine if the
percentage void filled bitumen results are compliant.
Test data:
Bitumen extraction and Marshall density and air void testing of samples were conducted
using Standard Operating Procedure.
The bulk density of the material has been measured with a nuclear density gauge and the
result supplied in CPA13. You will need to find the sensitivity coefficient for this
instrument.
The temperature at the time of analysis was recorded as 24 °C.
All drying was carried out at 105 °C.
The following documents are provided to you:
 CPA8 – Bitumen extraction test sheet – BE5003-2
 CPA9 – Product description – Measuring cylinder 2 L
 CPA10 – Calibration certificate – Analytical balance – AB5003-2
 CPA11 – Product description – Measuring cylinder 100 mL
 CPA12 – Product specifications – Oven – TO5003-2
 CPA13 – Test sheet – Marshall density and air voids – MDVA5003-2
 CPA14 – Calibration certificate – Analytical balance – AB5003-3
 CPA15 – Product specifications – Nuclear density gauge – NDG5003-1
Instructions:
Follow the six (6) steps as per the ISO GUM method to calculate and report the combined
standard uncertainty and expanded uncertainty.
Show your calculations below.
Answer the question at the end to determine if the test results are compliant.
Step 1: Describe the measurand
Complete Assessment v1.0 March 2020 Page 15

MSL925003 Determine measurements of uncertainty
The main aim of this experiment is to find the sensitivity coefficient of the nuclear density gauge.
This instrument was used in measuring the bulk density of the material. The lab temperature at
the time of analysis was 24oC and all drying were carried out at 105oC.
Apparatus used
 Analytical balance
 Centrifuge
 Suitable solvent
 Measuring cylinders
 Nuclear density gauge
 oven
In this experiment, bitumen extraction, Marshall density and air void testing were conducted.
Procedure;
 Accurately weigh 1201.45 g of asphalt sample (A)
 Dry this portion in a controlled temperature of 105 oc using the oven to obtain a
constant mass of 1109.11 g (C)
 Mass of the residue on the filter ring was found to be 0.26 g (F)
 Total mass of residue was found to be 0.85 g (I)
 Total volume of solvent was 1720 ml
 Volume of aliquot analysed was 92 ml
 Mass of fines in the fluid was then calculated
0.85*(1720/92) = 15.89 g (L)
Total mineral matter = (1109.11+0.26+15.89) = 1125.26 g
Weight of bitumen = (1201.45-1125.26) g = 76.1887 g
% bitumen = (76.1887/1201.45) *100 = 6.34%
 % air voids is calculated with reference to readings made from the nuclear density
gauge
 % air voids = 6.92
 % vol bitumen = 14.17
 % VFB = 67.17
Step 2: Identify sources of uncertainty
Complete Assessment v1.0 March 2020 Page 16
solvent Weighing
balance
Sensitivity

MSL925003 Determine measurements of uncertainty
Step 3: Quantify uncertainty
Balance; the experiment starts with numerous measurements made using the analytical balance.
The following information are obtained from the calibration certificate:
Repeatability = 0.005g from 10 trials
Sensitity offset = 0.03g
Linerity deviation = 0.01g
Repeatability checks are conducted in the calibration of the analytical balance as per the NATA
technical note. This therefore is a type A evaluation.the repeaterbility checks follows a normal
distributuion. Standard deviation is associated with the analytical balace.
Standard uncertainity = standard deviation(type A) obtained from quality control data
Total uncertainity of balance is calculated using RSS
Ubalance = (0.0052 + 0.032 + 0.012 )1/2
U balance =0.032016 g
Complete Assessment v1.0 March 2020 Page 17
Standard
flask repeatability
Uncertainity of balance
Componen
t
Uncertainit
y
Type Distributio
n
Standard uncertainity square
Repeatabili
ty
0.005 A Normal 0.005 0.000025
Sensitivity 0.03 A Normal 0.03 0.0009
Linearity 0.01 A Norrml 0.01 0.0001
Sum 0.001025
Square root 0.032001

MSL925003 Determine measurements of uncertainty
Balance;(maximum capacity 410g)
The following information are obtained from the calibration certificate:
Repeatability = 0.001g
Sensitity offset = 0.011g
Linerity deviation = 0.008g
Repeatability checks are conducted in the calibration of the analytical balance as per the NATA
technical note. This therefore is a type A evaluation.the repeaterbility checks follows a normal
distributuion. Standard deviation is associated with the analytical balace.
Standard uncertainity = standard deviation(type A) obtained from quality control data
Total uncertainity of balance is calculated using RSS
Ubalance = (0.0012 + 0.0112 + 0.0082 )1/2
Standard flask 2000ml
Calibration uncertaunity is ±8 ml .Assume triangular distribution
Standard uncertainity of calibration of sf =(10/61/2) = 4.0825 ml
Standard uncertainity of sf = 4 ml
Temperature: standard flask was calibrated at 21oc but bitumen extraction was done at 24oc
Coefficient of volume expansion of water = 2.1 * 10-4 oC
Volume variation = 2000 * 3 * 2.1 * 10-4 oC = 1.26 ml
Assuming rectangular distribution 1.26/1.73 = 0.72832 ml
Standard uncertainity for flask = Usf = (4.08252 + 42 + 0.728322 )1/2
Uncertainity of standard flask – 2000ml
Component Uncertainity Type Distribution Standard
uncertainity
Square
Complete Assessment v1.0 March 2020 Page 18
Uncertainity of balance
Componen
t
Uncertainit
y
Type Distributio
n
Standard uncertainity square
Repeatabili
ty
0.001 A Normal 0.001 0.000001
Sensitivity 0.011 A Normal 0.011 0.000121
Linearity 0.008 A Norrml 0.008 0.000064
Sum 0.000186
Square root 0.013638

MSL925003 Determine measurements of uncertainty
Repeaterbilit
y
4 A Normal 4 16
Temperature 1.26 B Resctangular 0.72832 0.53045
Accuracy 10 B Triangular 4.0825 16.6668
Sum 33.1972
Square root 5.762
Usf= 5.762
Standard flask 100ml
Calibration uncertaunity is 2 ml .assume triangular distribution
Standard uncertainity of calibration of sf =(10/61/2) = 4.0825 ml
Standard uncertainity of sf = 0.4 ml from 10 trials
Temperature: standard flask was calibrated at 20oc but bitumen extraction was done at 24oc
Coefficient of volume expansion of water = 2.1 * 10-4 oC
Volume variation = 100 * 4 * 2.1 * 10-4 oC = 0.084 ml
Assuming rectangular distribution 0.084/1.73 = 0.0485549 ml
Standard uncertainity for flask = Usf = (4.08252 + 0.42 + 0.04855492 )1/2
Uncertainity of standard flask – 100ml
Component Uncertainity Type Distribution Standard
uncertainity
Square
Repeaterbilit
y
2 A Normal 2 4
Temperature 0.084 B Resctangular 0.084 0.007056
Accuracy 10 B triangular 4.0825 16.6668
Sum 20.674
Square root 4.5469
Usf= 4.547
oven: all drying in this experiment were carried out at a controlled temperature of 105oc.
the following information are true for this product
temerature range: 10-200oc
control accuracy ± 0.20 oc
temperature uniformity ± 3oc
the moisture mass fraction wH2O, expresssed as g g-1 is the mass of water evaporated during the
sdample drying at 105oc to constant mass of 1109.11 g
Complete Assessment v1.0 March 2020 Page 19

MSL925003 Determine measurements of uncertainty
wH2O =( m(c+s) -m( c+s) dry)/m(c+s)-mc =0.094 assuming rectangular distribution
the dry matter mass fraction wDM,, is the dry residue content obtained afyet drying the sample at
105 oc
wDM = (m(c+s) dry –mc/m(c+s) –mc) = 0.922 assuming rectangular distribution
combined oven uncertainity = (0.922-0.094) = 0.828
Neuclear density gauge
The information about nuclear density gauge are obtained from its product specification.
The nuclear density gauge uses a count ratio in determining the density of a material according to
the following equation.
CR = A x e-Bρ – C ;
Sensitivity coefficient of the nuclear density gauge is 1.2.
Step 4: Calculate combined standard uncertainty
Uncertainity in determing %VFB
uncer
tainit
y
Descriptio
n
Distributio
n
Type Standard
uncertainit
y
Relative
uncertainit
y
Relative
variance
balan
ce
Mass Normal A 0.032016 0.000016 0.000012
Vf(2
L)
volume Rectangul
ar
B 5.762 0.002881 0.1588
Vf
(100
mL)
volume Rectangul
ar
B 4.547 0.04547 0.0227
Oven Heat Rectangul
ar
B 0.828 0.0414 0.0207
balan
ce
Mass normal A 0.013638 0.000033 0.0000165
sum 0.18152
Square
root
0.4261
Complete Assessment v1.0 March 2020 Page 20

MSL925003 Determine measurements of uncertainty
Step 5: Calculate expanded uncertainty
Number of measurement done =10
Degrees of freedom = n-1
= 10-1 = 9
Uncertainty is reported at 95% confidence level.
Using the student t table, the coverage factor is 2.262
Expanded uncertainty = 2.262* 0.4261 = 0.9638
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MSL925003 Determine measurements of uncertainty
Step 6: Report uncertainty
Combined standard uncertainty
The % VFB is 67.17 with a combined uncertainty of 0.4261%
Reporting expanded uncertainty
The void filled by bitumen in the asphalt sample is 67.17%±0.9638with a coverage factor of
2.262 on 9 degrees of freedom and estimated to have a confidence of 95%.
Determine compliance of test results
Determine if the results obtained for the expanded uncertainty are compliant/ fit for purpose if the
tolerance limits for the analysis is given as 10% of the result.
Show your workings and state the reasons for determining compliance.
Sample 1
10% of asphalt sample gives a %Bitumen of 6.7-7.9%
Results obtained along with uncertainty gives %Bitumen of 4.6% which is within tolerance limit
hence compliant.
Sample 2
10% of asphalt sample gives a % bitumen of 11%
Results obtained along with uncertainty gives a range of 12-14% which way beyond the tolerance
limit thus not compliant at 95% confidence level.
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MSL925003 Determine measurements of uncertainty
Recording Assessment Results
Unit code MSL925003 Determine measurements of uncertainty
Assessment Practical Assessment
Workplace evidence Task Document
* Documents listed as evidence MUST be attached to this assessment.
Student’s name
Student’s signature
Outcome ☐ Satisfactory ☐ Not-Yet Satisfactory
Assessor’s name Date
Assessor’s signature
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MSL925003 Determine measurements of uncertainty
Knowledge Assessment
Please read this information in conjunction with the important information on page 3 of this
assessment document:
1. To achieve a satisfactory result in this assessment you need to successfully complete
all questions.
2. This assessment is a conversational assessment with questions; you will be asked open
and leading questions in the course of a conversation with your assessor to ensure you
have the knowledge required of this unit.
3. In QLD, if performed as a verbal assessment, your answers must be recorded verbatim
(via sound recording).
4. If you do not answer a question satisfactorily, or in full, the question may be re-
phrased and asked again.
5. To gain further information, your assessor may ask questions not contained in this
document.
6. Knowledge questions may be completed as a written assessment. If completing as a
written assessment on hardcopy, you must only use black pen to complete. Whiteout,
pencils or other coloured pens are not acceptable.
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MSL925003 Determine measurements of uncertainty
1. Choose one of the tests you have performed in the laboratory, then briefly summaries the
steps involved in the test measurement.
Determination of % bitumen in asphalt sample
Apparatus
 Extraction bowl
 Centrifuge
 Filter rings
 Oven
 Analytical balance
 Measuring cylinders (2L and 100ml)
 Suitable solvent
Procedure;
 Using the accurately weigh the mass of asphalt sample (m1)
 Dry this sample in the oven at controlled temperatures of 105oc to obtain a constant
mass (m2)
 Tare the weight of the extraction bowl and weigh the test potion
 Prepare the test portion by mixing with the bitumen extraction solvent
 start the centrifuge to begin extraction
 measure the mass of residue obtained (m3)
 measure the mass of the total matter (m4)
 weight of bitumen (m1-m4)
 % bitumen = (weight of bitumen/mass of the asphalt sample) *100
2. List two (2) differences between errors, corrections and uncertainties.
Errors Corrections Uncertainty
The difference between the
observed measured value and
the true value in an experiment
is known as an error.
Errors are classified into
systematic and random errors.
Systematic errors have an
influence on the accuracy of
measurements. These errors
can be quantified. Systematic
Systematic inaccuracies are
rectified by application of
corrections.
Calibration techniques are
widely used in the correction of
systematic errors
Correction can be achieved by
adding or subtracting numerical
values to and from the
measured value.
The range within which the
true value may be found is
known as uncertainty.
There is type A uncertainty
and type B uncertainty as
explained by the GUM.
Calculation of type A
uncertainty depends on a
series of observations while
type B uncertainty are
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MSL925003 Determine measurements of uncertainty
errors are due to wrongly
calibrated instruments,
observational errors and
environmental errors.
Random errors have a slight
interference on the
measurements’ accuracy.
Random errors are hardly
eliminated from an experiment.
Random errors are due to
limitations of instruments,
variation in experimental
procedures and environmental
factors.
Besides, correction can be
achieved by multiplying or
dividing the measured value
with a specific factor
calculated using available
information.
Uncertainty is expressed as a
measured value; positive or
negative uncertainty.
3. Briefly explain the uncertainty involved in the uncertainty estimation process.
Uncertainty is determined for the purposes of presenting credible data in an experiment. However,
this process of determining uncertainties is not error free thus has uncertainty associated with it.
If data is obtained by varying all variables associated with a measurement, then uncertainty can be
evaluated by statistical analysis. However, due to time constraints this is impossible. Therefore,
this calls for the use of a mathematical model. In this model, its assumed that in a test procedure,
uncertainty can be estimated to the degree of the required accuracy.
Hence, the mathematical model of predicting uncertainty is not perfect and has unavoidable
uncertainties associated with it.
4. List two (2) sources of calibration uncertainty.
 Temperature variations
 Errors in the calibration procedures
5. Briefly explain how uncertainty from a calibrated instrument is accounted.
Instruments become unstable overtime thus giving false data. Electric or digital analytical
instruments are majorly affected by deviations in the magnetic field. Beside, these instruments are
sensitive to change in stimuli. Therefore, calibration is required in mitigating these uncertainties.
Calibration eliminates errors in analytical instruments by calculating the limit of performance. The
limit of performance is the upper limit of measurement error that may be expected when no
correction is made and only reading is taken.
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MSL925003 Determine measurements of uncertainty
6. How does the repeatability of results contribute to overall uncertainty of a test
measurement?
When carrying out a series of measurements, it is impossible to obtain identical results. This
creates uncertainty in test results.
7. How is the uncertainty from repeatability of results measured?
Standard deviation calculations are used in the measurement of uncertainty from repeatability of
results.
8. Briefly explain the importance of determining uncertainty from instrument resolution.
The resolution of measuring equipment affects the accuracy and precision of test results.
Resolution considers the limitation of measuring equipment thus making it very important.
9. List four (4) environmental factors that may contribute to uncertainty of measurement.
 Gravity
 Temperatures
 Humidity
 Pressure
 Vibrations
 Air droughts
10. Briefly explain how uncertainty due to environmental factors can be minimized.
Analytical balances are stabilised by being placed away from vibrating bodies and too much heat
from the sun. this equipment is also shielded to prevent fluctuations from air draught.
Analytical equipment should be operated in environmental conditions specified by the
manufacturer.
11. Briefly describe how you can identify the uncertainty of a Certified Reference Material.
Uncertainty of a certified reference material can be identified from certificate of analysis
12. List two (2) common factors which contribute to uncertainty when using a calibrated
instrument.
 Changes in the environment
 Using the instrument in conditions different to those of its calibration
13. How can uncertainty in reproducibility of results be minimised?
 Using simple direct test methods
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MSL925003 Determine measurements of uncertainty
 Internal checking
14. List the steps involved in estimating uncertainty as per the ISO GUM.
1. Describe the measurund
2. Identify uncertainity sources
3. Quantify uncertainity components
4. Convert components to standard uncertaininties
5. Determine significat sources of uncertainity
6. Calculate combined standard uncertainity
7. Calculate expanded uncertainity
8. Report uncertainity.
15. List five (5) typical sources of uncertainty in a chemical test method.
 Experimental conditions
 Calibration
 Wrong operator readings
 Sampling
 Blank correction
 glassware
16. Briefly explain the process of determining uncertainty components associated with each
of the inputs in a test measurement.
Use a fish and bone diagram in identifying the uncertainty components associated with each inputs
in a test measurement. One should describe the measurand. In describing the measurand, the
following are mentioned;
 Method used in analysis
 Components to be analysed
 Detailed calculations
17. List three (3) quality control data or resources that can be used to determine uncertainty
for Type B evaluation.
Uncertainty type B evaluation depends on the information available. This information are obtained
from;
 Quality reports
 Test results from previous similar tests
 Calibration report
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MSL925003 Determine measurements of uncertainty
18. Briefly explain the process of allocating an appropriate distribution to an uncertainty
component and the types of distribution that can be applied.
In allocating the right distribution to an uncertainty component, critical thinking and informative
judgment are used. Types of distributions include, normal, asymmetrical, rectangular and
triangular.
19. Briefly describe how significant sources of uncertainty can be determined?
Significance is calculated using the following equation
% significance =(individual standard uncertainity2/summation of all standard uncertinities2)
the following equation is true for significant uncertainty
uncertainty ≥ 5%.
20. Briefly describe how corrections are applied to test results.
Test results are corrected by adding or subtracting numerical to these results or by multiplying or
diving the results by the correction factor.
21. Identify two (2) pieces of information you can obtain from manufacturer’s specifications
when estimating uncertainty.
 Sensitivity drift
 Instrument drift.
 Repeatability
22. Define the term 'degrees of freedom'.
Degrees of freedom is the number of independent values which can be varied in a statistical
analysis.
23. How can degrees of freedom be calculated for Type B evaluations.
For type B uncertainty, the degree of freedom may be obtained in documents describing a
particular product.
Degree of freedom for type B = (1uB2/2ᵦ2)
UB2= type B uncertainty β = Type B variance
24. How can degrees of freedom be calculated for Type A evaluations.
For type A uncertainty the degree of freedom is calculated for the number of measuments (n);
Degree of freedom = n-1
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MSL925003 Determine measurements of uncertainty
25. State four (4) characteristics of a valid measurement.
 A valid measurement should have sufficient precision
 Valid measurement should have the capability of aiding valid decision making
 Valid measurement should be self-explanatory
 A valid measurement must be accurate
26. State the ISO standard relating to uncertainty of measurement.
ISO/IEC Guide 98:2009: Uncertainty of measurement is the international reference for
determination of uncertainty of measurement
27. Summarise the uncertainty reporting requirements as per the ISO Guide.
ISO guide requires that the following information should be included when reporting standard
uncertainty;
 Measurand description
 Degree of freedom estimation
 Provide the unit of measurement result ‘y’ and standard combined uncertainty ‘uc’
 Where appropriate the relative combined standard uncertainty should be included.
Relative standard combined uncertainty = ui(x)/x
The following is an expression for the standard combined uncertainty
Ms = x (units) with uc = u (units)
In reporting expanded uncertainty the following information must be included
 Value of each standard uncertainty
 Measurand description
 Value of coverage factor
 Sensitivity coefficients
 Level of confidence associated with uncertainty
 Relative expanded uncertainty
 Estimated covariance or correlation coefficients
 Degree of freedom for each uncertainty should be provided
 Show how each degree of freedom was obtained.
28. State the NATA reference document applicable for uncertainty measurement.
Estimating and reporting measurement uncertainty of chemical test results provides general
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MSL925003 Determine measurements of uncertainty
accreditation guidance related to uncertainty determination
29. Provide two (2) examples of unethical practices when estimating uncertainty.
 Deliberate overlook of a particular source of uncertainty of well-known effects.
 Data manipulation to attain smaller magnitudes of uncertainty.
30. Briefly describe two (2) circumstances when a standard becomes mandatory.
Standards are mandatory in the following circumstance;
 If a particular standard is needed by an accreditation body in order to achieve
accredation status
 If standards are points of reference in commonwealth legislation
31. Identify one (1) health hazard associated with the process of estimating uncertainty.
Boredom, fatigue and mental strain and stress.
Back pains as a result of longer sitting hours.
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MSL925003 Determine measurements of uncertainty
Recording Assessment Results
Unit code Unit code unit name
Assessment Knowledge Assessment
Student’s name
Student’s signature
Outcome ☐ Satisfactory ☐ Not-Yet Satisfactory
Assessor’s name Date
Assessor’s signature
Is there a sound recording of this assessment? Yes ☐ No ☐
If Yes, please submit with this
assessment.
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MSL925003 Determine measurements of uncertainty
Training Record
This Training Record is an important official record of the training a Trainee will receive
during the course of obtaining a nationally recognised qualification.
The Training Record lists all the units of competence, performance criteria and workplace
tasks a Trainee must successfully undertake in order to complete the qualification.
TRAINEE RESPONSIBILITIES
 Undertake all training tasks as requested by the workplace supervisor or LTT
Trainer/Assessor
 Ask for assistance if required contact your LTT Trainer/Assessor
 Acknowledge ability to perform workplace tasks.
EMPLOYER RESPONSIBILITIES
 Provide adequate and suitable training experiences to enable the Trainee to attain
competence
 Ensure that the Participant is supervised and guided at all times during the training
period
 Acknowledge competence in the workplace to industry and company standards by
reviewing the Training Record and
 signing to verify on a regular basis
 Advise LTT if any training issues arise.
How to use your Training Record
1. This Training Record contains all the competencies that relate to the skills and
knowledge you (the Participant) have to demonstrate in a practical way in the
workplace.
2. You have to show you can perform the competencies in this Training Record in a
workplace setting. When you can, you will be considered competent at those
particular tasks.
3. The units of competency are divided into smaller elements and performance criteria
that is, specific tasks you will be asked to show you can do. You must be observed in
your workplace and assessed as being competent by your Trainer/Assessor, assisted
by your Workplace Supervisor and any other relevant observer.
4. Assessment is not graded. It is either: Competent or Not Yet Competent
5. To be considered competent, you need to demonstrate skills: consistently, and to the
standard required.
6. Your Workplace Supervisor and your Trainer/Assessor will both be involved in
teaching and assessing you in the workplace throughout your traineeship.
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MSL925003 Determine measurements of uncertainty
7. If you do not keep up the expected standard after being assessed as competent, you’re
Workplace Supervisor and your Trainer/Assessor can, in consultation with you,
reverse the assessment after you have been notified
8. It is the Participant’s responsibility (your job) to check that all competencies have
been signed off by your Trainer/Assessor and Workplace Supervisor before you
submit your Training Record to your Trainer/Assessor for final assessment.
Unit of Competency Training Record (Supervisor Use Only)
MSL925003 Determine measurements of uncertainty
Task Tick Supervisor
Initials
Is able to specify an equation for the measurement ☐
Lists uncertainty components associated with each input in the equation ☐
Calculates standard deviations and the standard deviations of the mean
from the measurement results ☐
Uses calibration reports, manufacturer's specifications, quality control
and validation data, and experimental data to collect other available
information on the uncertainty components
☐
Designates appropriate distribution for each uncertainty component ☐
Is able to calculate the standard uncertainties ☐
Is able to calculate the sensitivity coefficient for each uncertainty
component ☐
Is able to calculate a combined standard uncertainty ☐
Determines appropriate coverage factors based on the degrees of
freedom associated with each uncertainty component ☐
Is able to calculate the expanded uncertainty ☐
Reports all results and uncertainty using appropriate units and
significant figures ☐
Reports the confidence level and coverage factor ☐
Ascertains the appropriateness of the size of the expanded uncertainty
relative to the tolerance or required accuracy of the test ☐
Ascertains the fitness for purpose of the expanded uncertainty relative
to the use of the measurement result ☐
Comments
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MSL925003 Determine measurements of uncertainty
Declarations
MSL925003 Determine measurements of uncertainty
I confirm this to be a true account of the processes and practices demonstrated in the
workplace
Student
Name: Signature: Date
:
Supervisor
Name: Signature: Date
:
I am satisfied the above student has demonstrated competence to industry and company
standards.
Trainer
Name: Signature: Date
:
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MSL925003 Determine measurements of uncertainty
Unit of Competency Completion Record (Assessor Use Only)
UOC code and title MSL925003 Determine measurements of uncertainty
Student name
Student number Outcome
Completion date MUST reflect the exact date as on the stated Assessment Task.
Assessment Tasks
Adjust tasks as
necessary to
correspond to
required assessment
methods for UOC
Completion Date Satisfactory Not yet
satisfactory
Knowledge
Assessment ☐ ☐
Practical Assessment ☐ ☐
Training Record ☐ ☐
Feedback to Candidate
Student has received the above written feedback for this unit
of competency
(Convert to PDF if sending electronically)
☐
Assessment Result Competent ☐ Not Competent ☐
Date
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MSL925003 Determine measurements of uncertainty
Assessor Name
Assessors signature
Complete Assessment v1.0 March 2020 Page 37