NZQA Expiring unit standard
2641 version 6
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Title
Demonstrate knowledge of analytical measurement systems
Level
4
Credits
6
Purpose
People credited with this unit standard are able to demonstrate
knowledge of:
– pH measurement;
– conductivity measurement;
– dissolved oxygen measuring equipment;
– stack and/or particulate monitoring equipment;
– chromatography measuring equipment;
– consistency and viscosity measuring equipment;
– humidity measuring equipment;
– density measuring equipment; and
– analytical sampling systems.
Classification
Industrial Measurement and Control > Industrial Measurement
and Control - Theory
Available grade
Achieved
Explanatory notes
This unit standard has been developed for learning and assessment off-job.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of pH measurement.
Evidence requirements
1.1
The term pH and its associated scale are defined.
Range
1.2
positive hydrogen ions, 14 alkaline, 3 acidic, 7 neutral, log scale.
Components of a pH measuring system are identified and described.
Range
reference electrode, measuring electrode, temperature
compensation, very high input impedance amplifier.
1.3
Operating principles of the pH measuring system are described.
1.4
Calibration methods for pH measuring systems are identified.
The Skills Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
Range
1.5
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buffer solution, backing off unwanted e.m.f.s.
Problems associated with pH measuring systems are identified.
Range
electrode cleaning, ultrasonic, mechanical wiping, lead wire
connections, probe failure.
Outcome 2
Demonstrate knowledge of conductivity measurement.
Evidence requirements
2.1
Principles of conductivity measurement are described.
Range
2.2
Factors taken into account when making conductivity measurements are
defined.
Range
2.3
siemens, micro mho, electrolyte.
non-linear solution strengths, temperature compensation, probe
constant.
Calibration techniques are described.
Range
amplifier decade box injection, dedicated test equipment, standard
solutions.
Outcome 3
Demonstrate knowledge of dissolved oxygen measuring equipment.
Evidence requirements
3.1
Principles of dissolved oxygen measurement are stated.
Range
galvanic cell, polarographic cell.
3.2
Air exposure at valve glands, and its prevention, is explained in relation to
making dissolved oxygen measurements.
3.3
Calibration techniques are described.
Range
transmitter adjustment, sample 5% sodium sulphite, water
saturated air.
Outcome 4
Demonstrate knowledge of stack and/or particulate monitoring equipment.
Evidence requirements
The Skills Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
4.1
Principles of stack and/or particulate monitoring are stated.
Range
4.2
dichotomous sampler particulate, infra red, zirconia probe, light
attenuation/transmissiometer, Carbon Monoxide (CO), Carbon
Dioxide (CO2), Nitrous Oxide (NO), particulate.
Factors taken into account when making stack monitoring measurements are
defined.
Range
4.3
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air dilution, water vapour, plant operating conditions, wet sample,
dry sample.
Calibration techniques are described.
Range
dedicated test equipment, sample.
Outcome 5
Demonstrate knowledge of chromatography measuring equipment.
Evidence requirements
5.1
Principles of chromatography and detectors are stated.
Range
5.2
thermal conductivity, flame ionisation, carrier gas, packed column,
measuring circuit.
Typical measurement applications using chromatography are identified, and
graphical read outs are described.
Range
liquid, gas, vapour samples.
Outcome 6
Demonstrate knowledge of consistency and viscosity measuring equipment.
Evidence requirements
6.1
Types and uses of consistency transmitters are described.
Range
6.2
pulp stock, shear forces, force balance, blade type, rotating.
Types and uses of viscosity transmitters are described.
Range
oil, liquid, rotational, capillary, float.
Outcome 7
Demonstrate knowledge of humidity measuring equipment.
Evidence requirements
The Skills Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
7.1
Areas of application for humidity measurements are defined.
Range
7.2
dew point, relative humidity, saturated solution, saturation
pressure, specific humidity, hygrometer.
Relative humidity is determined by using psychometric chart and hygrometer.
Range
7.4
pulp and paper, powder plant.
Principles and terms involved in humidity measurements are stated.
Range
7.3
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sling psychometer, wet-dry bulb hygrometer.
Hygrometer types are described.
Range
chilled mirror type, surface conductivity type.
Outcome 8
Demonstrate knowledge of density measuring equipment.
Evidence requirements
8.1
Terms and units used in density measurement are defined, and examples are
converted by calculations.
Range
8.2
kilograms per cubic metre (kg/m³), relative density, specific gravity.
Methods of density measurement using differential pressure transmitters are
described and their applications stated.
Range
constant level over flow, reference wet leg, twin bubble tube.
8.3
Methods of density measurement using displacement transmitters are
described and their applications stated.
8.4
Methods of density measurement using weighing of the fixed volume of product
are described and their applications stated.
8.5
Methods of density measurement using nuclear radiation are described and
their applications stated.
8.6
Methods of density measurement using refractometers and sonic measuring
equipment are described and their applications stated.
8.7
Methods of density measurement using vibrating mass type measuring
equipment are described and their applications stated.
Outcome 9
Demonstrate knowledge of analytical sampling systems.
The Skills Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
2641 version 6
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Evidence requirements
9.1
Steps to obtain and process an analytical sample are stated and shown in a
block diagram.
Range
9.2
sample taken, transport to analyser, condition sample, exhaust
sample.
Sampling system components are stated.
Range
pumps, filters, scrubbers, dryers, phase separating devices,
vaporisers, heat exchangers.
Replacement information
This unit standard has been replaced by unit standard
28080 and unit standard 28081.
This unit standard is expiring. Assessment against the standard must take place by
the last date for assessment set out below.
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
31 October 1995
31 December 2013
Revision
2
30 October 1997
31 December 2013
Revision
3
3 April 2001
31 December 2013
Review
4
22 June 2001
31 December 2013
Review
5
19 May 2008
31 December 2017
Review
6
28 November 2013
31 December 2017
Consent and Moderation Requirements (CMR) reference
0003
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMR). The
The Skills Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016
NZQA Expiring unit standard
2641 version 6
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CMR also includes useful information about special requirements for organisations wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
The Skills Organisation
SSB Code 100401
 New Zealand Qualifications Authority 2016