SAQA All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.
SOUTH AFRICAN QUALIFICATIONS AUTHORITY 
REGISTERED UNIT STANDARD: 

Perform DC electrical and resistance measurements and calibrate devices. 
SAQA US ID UNIT STANDARD TITLE
119254  Perform DC electrical and resistance measurements and calibrate devices. 
ORIGINATOR
SGB Engineering 
PRIMARY OR DELEGATED QUALITY ASSURANCE FUNCTIONARY
-  
FIELD SUBFIELD
Field 06 - Manufacturing, Engineering and Technology Engineering and Related Design 
ABET BAND UNIT STANDARD TYPE PRE-2009 NQF LEVEL NQF LEVEL CREDITS
Undefined  Regular  Level 5  Level TBA: Pre-2009 was L5  17 
REGISTRATION STATUS REGISTRATION START DATE REGISTRATION END DATE SAQA DECISION NUMBER
Reregistered  2018-07-01  2023-06-30  SAQA 06120/18 
LAST DATE FOR ENROLMENT LAST DATE FOR ACHIEVEMENT
2024-06-30   2027-06-30  

In all of the tables in this document, both the pre-2009 NQF Level and the NQF Level is shown. In the text (purpose statements, qualification rules, etc), any references to NQF Levels are to the pre-2009 levels unless specifically stated otherwise.  

This unit standard does not replace any other unit standard and is not replaced by any other unit standard. 

PURPOSE OF THE UNIT STANDARD 
Since Metrology covers a wide spectrum of measurement disciplines, this unit standard should be seen as covering only one of the disciplines. Although many metrology processes are similar, there are distinct competency differences between various technically specialized parameters within each discipline.

This unit standard will be useful to metrologists who are required to perform measurements and calibrations within the DC discipline in the following parameters:

DC Voltage
DC Current
Resistance

Persons credited with this unit standard are able to calibrate devices and artefacts for metrology. This includes all aspects related to the work of performing measurements and maintaining the necessary standards and transferring accuracy traceability from National Measurement Standards to a unit under test.

The Metrology process, referred to above, is generically the same for all disciplines within metrology fields, but the embedded knowledge is uniquely different. The process is to:
  • Maintain reference standards
  • Derive, generate and measure quantities and calibrate devices.
  • Record, evaluate and report the results 

  • LEARNING ASSUMED TO BE IN PLACE AND RECOGNITION OF PRIOR LEARNING 
    Competence in the following:
  • Mathematics at level 5.
  • Natural Science at level 5.
  • Define the role, functions and operation of the international measurement system.
  • Statistics at level 5.
  • Apply the ISO document "Guide to the expression of uncertainty in measurement" to estimate uncertainty of measurement.
  • Develop calibration and test methods and procedures.
  • Reporting measurement results.
  • Use and maintenance of hand tools, power tools and measuring instruments.
  • Draw, read and interpret basic electrical/electronic circuit drawings. 

  • UNIT STANDARD RANGE 
    N/A 

    Specific Outcomes and Assessment Criteria: 

    SPECIFIC OUTCOME 1 
    Maintain DC electrical and Resistance reference standards. 

    ASSESSMENT CRITERIA
     

    ASSESSMENT CRITERION 1 
    Evidence of the source of traceability selected, has international equivalence. 

    ASSESSMENT CRITERION 2 
    Calibration intervals are determined from analysed data of reference standards' records. 

    ASSESSMENT CRITERION 3 
    Reference standards are maintained in a condition fit for purpose. 

    ASSESSMENT CRITERION 4 
    Reference standards are verified to be fit for intended purpose, data recorded and corrective action implemented for failures. 

    ASSESSMENT CRITERION 5 
    Maintenance records for reference standards have been generated and kept up to date. 
    ASSESSMENT CRITERION RANGE 
    "Maintenance records" refers to calibration certificate; record cards; verification data; control charts; etc
     

    ASSESSMENT CRITERION 6 
    Laboratory environmental conditions are within required limits and records are kept. 

    ASSESSMENT CRITERION 7 
    Reference standards are maintained to within an uncertainty in support of the required measurement capability. 
    ASSESSMENT CRITERION RANGE 
    "Reference standards" refers to national measurement standards, laboratory standards, working standards and shop-floor standards
     

    SPECIFIC OUTCOME 2 
    Derive, generate and measure DC electrical and Resistance quantities and calibrate electrical devices. 

    ASSESSMENT CRITERIA
     

    ASSESSMENT CRITERION 1 
    Measurement method selected, derives the parameter, and satisfies the range and accuracy required. 
    ASSESSMENT CRITERION RANGE 
    DC Voltage - Potentiometer, voltage division, direct measurement, differential measurement.
    DC Current - Current-volt drop, direct measurement.
    Resistance - Current-volt drop, substitution (multimeter, Wheatstone bridge), voltage injection, direct measurement.
     

    ASSESSMENT CRITERION 2 
    Measurement set-up is according to procedure. 

    ASSESSMENT CRITERION 3 
    Number of measurements performed, satisfies precision required. 

    ASSESSMENT CRITERION 4 
    Calibration/measurement points selected, satisfies range and accuracy required. 

    ASSESSMENT CRITERION 5 
    Equipment handled according to appropriate specifications and/or safety requirements. 

    ASSESSMENT CRITERION 6 
    Measurements taken as per procedure. 

    SPECIFIC OUTCOME 3 
    Record, evaluate and report results. 

    ASSESSMENT CRITERIA
     

    ASSESSMENT CRITERION 1 
    Measurement raw data is recorded as per procedure. 

    ASSESSMENT CRITERION 2 
    Raw data is evaluated for conformance to required accuracy specifications. 

    ASSESSMENT CRITERION 3 
    Adjustments are made, if necessary. 

    ASSESSMENT CRITERION 4 
    An appropriately detailed measurement report/certificate is generated for given measurement results in accordance with ISO / IEC 17025. 


    UNIT STANDARD ACCREDITATION AND MODERATION OPTIONS 
    Anyone assessing a learner against this unit standard must be a registered SANAS Technical Assessor and registered as an assessor with the relevant ETQA.

    Any institution offering learning that will enable achievement of this unit standard must be accredited as a provider through the relevant ETQA by SAQA.

    Moderation of assessment will be overseen by the relevant ETQA according to the moderation guidelines and the agreed ETQA procedures. 

    UNIT STANDARD ESSENTIAL EMBEDDED KNOWLEDGE 
    Essential embedded knowledge will be assessed through assessment of the specific outcomes in terms of the stipulated assessment criteria. Candidates are unlikely to achieve all the specific outcomes, to the standards described in the assessment criteria, without knowledge of the listed embedded knowledge. This means that for the most part, the possession or lack of the knowledge can be directly inferred from the quality of the candidate's performance. Where direct assessment of knowledge is required, assessment criteria have been included in the body of the unit standard.

    The following embedded knowledge is addressed in an integrated way in the unit standard:

    2.1. DC Voltage.

    Ohm's law, Circuit element, Weston cells, Solid State Voltage References, Josephson Junction Array Voltage Standard (JJAVS).

    2.2. Resistance.

    Resistor types, Formula for resistance, Required properties, Pure metals, Resistance Alloys, Temperature Coefficient of Resistance, Thomas Type (1ohm) Standards, Low TC Resistors, Lindeck Element, Wheatstone bridge, Kelvin Double Bridge, Three-terminal Resistors, Quantum Hall Resistance.

    2.3. Voltage Dividers.

    Kelvin-Varley Divider.
  • Specification
  • Design principle
  • Self-calibration
  • Applications

    Series/Parallel Divider (1kV).
  • Specification
  • Self-calibration
  • Simplified diagram
  • Sources of Ratio uncertainty
  • Application
    High Voltage Probes.

    2.4. Electrical Calibration of Temperature Measuring Instruments. 

  • UNIT STANDARD DEVELOPMENTAL OUTCOME 
    N/A 

    UNIT STANDARD LINKAGES 
    N/A 


    Critical Cross-field Outcomes (CCFO): 

    UNIT STANDARD CCFO IDENTIFYING 
    Identify and solve problems and make decisions using critical and creative thinking.
    Note: The ability of the candidate to identify incorrect conditions with reference standards, incorrect measurements taken for a specific parameter, assess and taken appropriate action - Refer to all "Specific Outcomes". 

    UNIT STANDARD CCFO WORKING 
    Work effectively with others as members of a team, group, organisation or community.
    Note: The ability and willingness of the candidate to accept and interpret work instructions and calibration/measurement procedures from customers correctly and to request assistance in an appropriate manner as a team member - Refer to "Specific Outcome" 3.
    3. Record, evaluate and report results. 

    UNIT STANDARD CCFO ORGANISING 
    Organise and manage themselves and their activities responsibly and effectively.
    Note: The preparation for measurement of electrical devices, the maintenance of reference standards, the candidate must indicate what tools, equipment, set-up and calibration procedures is required and communicates to fellow workers and laboratory manager his/her intentions - Refer to all "Specific Outcomes". 

    UNIT STANDARD CCFO COLLECTING 
    Collect, analyse, organise and critically evaluate information.
    Note: The ability of the candidate to reconcile the measured data and information from the visual examination and constantly evaluate the changing situation - Refer to all "Specific Outcomes". 

    UNIT STANDARD CCFO COMMUNICATING 
    Communicate effectively, using visual, mathematical and / or language skills in the modes of oral and / or written presentations.
    Note: The appropriate communication with customers, laboratory manager and personnel with regard to maintenance of Reference Standards, calibration and/or testing of equipment and artefacts and the measurement results achieved, will indicate his/her proficiency in effective communication. 

    UNIT STANDARD CCFO SCIENCE 
    Use science and technology effectively and critically showing responsibility towards the environment and health of others.
    Note: The ability of the candidate to effectively use the knowledge gains to inform and protect the broader environment and health of others - Refer to all "Specific Outcomes". 

    UNIT STANDARD CCFO DEMONSTRATING 
    Demonstrate an understanding of the world as a set of related systems by recognising that problem-solving contexts do not exist in isolation.
    Note: The ability of the candidate to understand the inter relationship between electrical measurements, maintenance and calibration of standards, reporting of results and their effect on global activities - Refer to all "Specific Outcomes". 

    UNIT STANDARD ASSESSOR CRITERIA 
    N/A 

    REREGISTRATION HISTORY 
    As per the SAQA Board decision/s at that time, this unit standard was Reregistered in 2012; 2015. 

    UNIT STANDARD NOTES 
    Notes to assessors

    Assessors should keep the following principles in mind when designing and conducting assessments against this unit standard:
  • Focus the assessment activities on gathering evidence in terms of the main outcome expressed in the title to ensure assessment is integrated rather than fragmented. Remember we want to declare the person competent in terms of the title. Where assessment at title level is unmanageable, then focus assessment around each specific outcome, or groups of specific outcomes.
  • Make sure evidence is gathered across the entire range, wherever it applies. Assessment activities should be as close to the real performance as possible, and where simulations or role-plays are used, there should be supporting evidence to show the candidate is able to perform in the real situation.
  • Do not focus the assessment activities on each assessment criterion. Rather make sure the assessment activities focus on outcomes and are sufficient to enable evidence to be gathered around all the assessment criteria.
  • The assessment criteria provide the specifications against which assessment judgements should be made. In most cases, knowledge can be inferred from the quality of the performances, but in other cases, knowledge and understanding will have to be tested through questioning techniques. Where this is required, there will be assessment criteria to specify the standard required.
  • The task of the assessor is to gather sufficient evidence, of the prescribed type and quality, as specified in this unit standard, that the candidate can achieve the outcomes again and again and again. This means assessors will have to judge how many repeat performances are required before they believe the performance is reproducible.
  • All assessments should be conducted in line with the following well documented principles of assessment: appropriateness, fairness, manageability, integration into work or learning, validity, direct, authentic, sufficient, systematic, open and consistent

    Unit standard justification

    1. Level

    Attribute-Level
    Applied Competence-5
    Autonomy of learning-5

    Actual Level Assigned: 5

    2. Credits

    Total hours required by the learner to achieve the required outcome:

    Activity-Hours
    Classroom Teaching-40
    On-The-Job Training-80
    Mentoring required-50
    Other (Specify)--
    Total-170

    Credits Assigned: 17 

  • QUALIFICATIONS UTILISING THIS UNIT STANDARD: 
      ID QUALIFICATION TITLE PRE-2009 NQF LEVEL NQF LEVEL STATUS END DATE PRIMARY OR DELEGATED QA FUNCTIONARY
    Elective  57228   National Certificate: Metrology  Level 5  Level TBA: Pre-2009 was L5  Reregistered  2023-06-30  EWSETA 


    PROVIDERS CURRENTLY ACCREDITED TO OFFER THIS UNIT STANDARD: 
    This information shows the current accreditations (i.e. those not past their accreditation end dates), and is the most complete record available to SAQA as of today. Some Primary or Delegated Quality Assurance Functionaries have a lag in their recording systems for provider accreditation, in turn leading to a lag in notifying SAQA of all the providers that they have accredited to offer qualifications and unit standards, as well as any extensions to accreditation end dates. The relevant Primary or Delegated Quality Assurance Functionary should be notified if a record appears to be missing from here.
     
    1. NATIONAL METROLOGY INSTITUTE OF SOUTH AFRICA 



    All qualifications and part qualifications registered on the National Qualifications Framework are public property. Thus the only payment that can be made for them is for service and reproduction. It is illegal to sell this material for profit. If the material is reproduced or quoted, the South African Qualifications Authority (SAQA) should be acknowledged as the source.