NLA-PT-C-P-31-03 Page 1 of 13 Date of Issue:

2017-10-27

National Laboratory Association of South Africa - NPC

P.O. Box 298 1 De Havilland Crescent

Persequor Park Persequor Technopark

Pretoria, South Africa, 0020

Reg. No: 1994/002856/08

Tel: (+27) 012 349 1500

Fax: (+27) 012 349 1501

http://www.nla.org.za

Measurement Protocol for the calibration of a Fluke 744

Process Calibrator

ILC 132

Compiled by: Approved By:

Floris van der Walt Steve Sidney

NLA-PT-C-P-31-03 Page 2 of 13 Date of Issue:

2017-10-27

Contents Page

1. Introduction -------------------------------------------------------------------------------- Page 3 2. Participants -------------------------------------------------------------------------------- Page 3 3. Organisation ------------------------------------------------------------------------------- Page 3 4. Confidentiality ----------------------------------------------------------------------------- Page 4 5. ILC Artefact Description ---------------------------------------------------------------- Page 4 6. Financial Liabilities ----------------------------------------------------------------------- Page 4 7. Reference Value -------------------------------------------------------------------------- Page 4 8. Analysis of Scheme Results ----------------------------------------------------------- Page 4 9. Operating Features ---------------------------------------------------------------------- Page 5 10. Measurement Instructions -------------------------------------------------------------- Page 5 11. Measure and Source Modes ---------------------------------------------------------- Page 6 12. Submission of Results ------------------------------------------------------------------ Page 6 13 Artefact Damaged or Unstable ------------------------------------------------------- Page 7 14. Appendix 1 (Measurement Result Form) ------------------------------------------- Page 7

NLA-PT-C-P-31-03 Page 3 of 13 Date of Issue:

2017-10-27

1. Introduction

This Proficiency Testing Scheme (PT) is designed to evaluate the participant laboratories’ competence in the calibration of a Process Calibrator in both Measure and Source modes. Participation by both accredited and non-accredited laboratories is welcomed.

The PT should enable SANAS accredited calibration laboratories, in the Electrical and

Temperature metrology fields, to demonstrate their capability over the relevant range/points. For most accredited laboratories, the accuracy of the PT artefact has been specifically

chosen such that the measurement results should be capable of proving satisfactory performance.

2. Participants This PT Scheme is open to all calibration laboratories capable of measuring and sourcing

AC & DC voltages, frequency, resistance, DC current, temperature or can perform temperature simulations for the purpose of calibrating Process Calibrators.

3. Organisation This Scheme is “closed” in nature meaning that it has defined start and end dates together

with a defined date by which the final report will be issued. A schedule is planned beforehand, allocating specific 1 week time-slots to pre-registered participating laboratories.

The Scheme is run as a “Star-shaped” scheme in that the artefact is returned back to the NLA – SA (for South Africa) or to the appointed agent (for International participants), in between participants. The artefact will be couriered from one participant to the next, being delivered by the Monday of the participant’s scheduled week (before 12h00) and collected on the Friday of the participant’s scheduled week (after 12h00). The cost of these courier services is already covered in the cost of the scheme and all that is required is for the participating laboratory to notify the NLA – SA to arrange for the collection by the courier. It should be noted that failure to have the ILC artefact ready for collection at the scheduled time, will have a severe knock-on effect on all future participants. Laboratories are therefore respectfully requested to rigidly adhere to the timing schedule. Failure to meet the allocated time may result in disqualification of the participant without refund.

Verification measurements will be performed by the NLA – SA in the middle of the scheme and at the end of the scheme.

Potential participants will be made aware of the scheme by means of direct E-mail notification, and requested to register should they want to participate. They will then be required to pay the participation fee, upon receipt of which they will be scheduled for participation.

The participants will receive the artefact via courier in their allotted one week time slot during which they must perform their measurements. They are then required to submit their measurement results to the NLA – SA within one week after participation.

A final report will be issued to the participants by the scheduled date which will contain the results obtained by each of the participants against the scheme Reference Value. The report will also contain the Normalised Error (En) values obtained by each laboratory.

NLA-PT-C-P-31-03 Page 4 of 13 Date of Issue:

2017-10-27

Normalised Error values ≤ 1 indicate satisfactory performance of the participant within their reported measurement uncertainties. Normalised Error values > 1 indicate unsatisfactory performance of the participant which require investigation (root cause analysis) and subsequent corrective action.

4. Confidentiality The identity of participants’ results will be kept confidential by means of a unique code known

only to the participant. Note: As per agreement between the NLA – SA and SANAS, and the permission of

SANAS accredited participants, the final report together with the identity of each accredited participant’s results, will also be made available to SANAS. The identity of all participants will remain confidential and their identity will not be made available to SANAS.

5. ILC Artefact Description The artefact is a Process Calibrator. Manufacturer: Fluke Model: 744 Serial Number: 7491007 6. Financial Liabilities

Each participant is responsible for the following costs:-

- The participation fee.

- Performing the measurements according to the requirements as laid down in the instructions and reporting the results.

- Any damage to the artefact whilst in their possession which includes in their

laboratory. Delivery notes and receipt condition forms will be used to transfer custody between the participant and the courier company.

7. Reference Value The Reference Value/s, including uncertainties, for this PT Scheme will be established by

consensus values and will only be done after all participants have submitted their results. 8. Analysis of Scheme Results

The measurement results together with their associated uncertainties of measurement, as reported by the participants, will then be used to calculate “Normalised Error” (En) values as follows:-

REFLAB

n

UU

REFLABE

22

NLA-PT-C-P-31-03 Page 5 of 13 Date of Issue:

2017-10-27

Where:- “REF” is the Reference Value obtained as described in para 7 above.

“LAB” is the value reported by the participating laboratory.

“UREF” is the Expanded Uncertainty at a Level of Confidence of 95,45% assigned to the Reference Value as described in para 7 above.

“ULAB” is the Expanded Uncertainty at a Level of Confidence of 95,45%

reported by the participant. 9. Operating Features

9.1 The Fluke 744 is a very versatile instrument and it is thus impractical to lay out the step by step operation of the instrument in this protocol. A complete user’s manual has been supplied with the instrument to enable the user to look up the relevant connection points and push button operations required to configure the instrument for the various functions.

10. Measurement Instructions

10.1 It should be noted that the artefact, should be treated in exactly the same way that any item that is brought into your laboratory would normally be treated. One of the purposes of conducting such a PT is to establish whether under ‘normal conditions” all laboratories can produce comparable results.

10.2 On arrival of the Fluke 744, a visual inspection is to be conducted and the results

reported to the NLA-SA using the form provided (Appendix 1). 10.3 There is no battery charger included with the Fluke 744 so the participant is requested

to do all the measurements with the battery eliminator (power supply) plugged in. Allow the instrument to warm up.

10.4 Refer to the supplied Operator/User’s Manual for the Fluke 744 Process Calibrator

and set the Fluke 744 to the functions, ranges and measurement points as per the attached result sheet (See Appendix 1) and record the measured/source value at each point.

10.5 In the event that there is a measure/source function required by the protocol that

cannot be done by the laboratory (such as frequency), the participant can skip that specific function and write on the result sheet “not participating”.

10.6 No specific environmental conditions are required during the measurements.

11. Measure and Source Modes

11.1 Measure Mode

When the protocol refers to “Measure Mode” the Fluke 744 is to be placed in the measurement mode and the laboratory is required to supply the source which will then be measured by the Fluke 744 and recorded as such.

NLA-PT-C-P-31-03 Page 6 of 13 Date of Issue:

2017-10-27

11.2 Source Mode

When the protocol refers to “Source Mode” the Fluke 744 is to be placed in the source mode to generate the required signal and the laboratory equipment must be used to measure the output of the Fluke 744 and recorded as such.

12. Submission of Results The results must be submitted to the NLA – SA Office within 1 week of the completion of the

measurements. The measurement results, together with the estimated Expanded Measurement

Uncertainties for a Level of Confidence of 95,45% must be reported on the attached result sheet (See Appendix 1).

NOTE: These uncertainties should be the calculated values and need not be limited to the participant’s SANAS accredited Measurement Capabilities. Since no calibration certificate is issued bearing the SANAS accreditation symbol, the SANAS limitations do not apply.

The results must either be faxed to +27 12 349-1501 or E-mailed to florisvdw@nla.org.za. 13. Artefact Damaged or Unstable

13.1 Should you find that on inspection the artefact is physically damaged you are to immediately inform the organizer (NLA – SA).

13.2 Depending on the outcome of the damage a decision will be made as to whether the

measurements can still be made or further remedial action is required. 13.3 In the event that the problem cannot satisfactorily resolved all participants will be

informed of either a delay in conducting the scheme or the cancellation of the scheme entirely.

13.4 The same process mentioned in 13.1 – 13.3 will be used should the artefact appear

to be unstable.

NLA-PT-C-P-31-03 Page 7 of 13 Date of Issue:

2017-10-27

Appendix 1

Measurement Result Form

1. Participant Details

Company Name

Contact name

Address

Calibrated by

Telephone Number

E-mail Address

Date/s of calibration

For SANAS accredited participants only:

I/We agree that the reported results for this laboratory will be made available to SANAS by the NLA-SA as part of the process. ____________________ ____________________ Name Signature _____________________

Date

2. Results Refer to the tables on next pages.

NLA-PT-C-P-31-01 Page 8 of 13 Date of Issue:

2017-10-05

2.1 MEASUREMENT MODE FUNCTIONS 2.1.1 DC Voltage – Measure mode

Fluke 744

Mode

Nominal Voltage

Fluke 744 Function

Measured Voltage

(V)

Measurement Uncertainty

(± V)

Measure -48 V DC V

Measure 24 V DC V

Measure 180 V DC V

2.1.2 AC Voltage – Measure mode (Sine wave)

Fluke 744

Mode

Nominal Voltage (V rms)

Frequency

(Hz)

Fluke 744 Function

Measured Voltage

(V)

Measurement Uncertainty

(± V)

Measure 30 V 60 AC V

Measure 230 V 60 AC V

NLA-PT-C-P-31-01 Page 9 of 13 Date of Issue:

2017-10-05

2.1.3 Frequency – Square Wave into the Fluke 744, 5 MΩ input impedance - Measure mode

Fluke 744

Mode

Nominal Frequency

(Hz)

Nominal

Voltage

(Vp-p)

Fluke 744 Function

Measured Frequency

(Hz)

Measurement Uncertainty

(± Hz)

Measure 100 1 Hz

Measure 1000 1 Hz

` 2.1.4 Resistance – Measure mode

2.1.5 DC Current - Measure mode

Fluke 744

Mode

Nominal Current

(mA)

Fluke 744 Function

Measured Current

(mA)

Measurement Uncertainty

(± mA)

Measure 4 DC Current

Measure 100 DC Current

Fluke 744

Mode

Nominal Resistance

(Ω)

Fluke 744 Function

Measured Resistance

(Ω)

Measurement Uncertainty

(± Ω)

Measure 100 Resistance

Measure 5000 Resistance

NLA-PT-C-P-31-01 Page 10 of 13 Date of Issue:

2017-10-05

2.1.6 Thermocouple (Type K) (Fluke 744 internal CJC) (ITS 90) – Measure mode

Fluke 744

Mode

Simulated Temperature

(°C)

Fluke 744 Function

(°C)

Measured Temperature

(°C)

Measurement Uncertainty

(°C)

Measure -20 Thermocouple

Measure 50 Thermocouple

Measure 100 Thermocouple

2.1.7 PT100 (385) Platinum Resistance Temperature Detector (RTD) (ITS 90) (4 Wire) – Measure mode

Fluke 744

Mode

Simulated Temperature

(°C)

Fluke 744 Function

(°C)

Measured Temperature

(°C)

Measurement Uncertainty

(± °C)

Measure -50 RTD (PT-100) (385)

Measure -10 RTD (PT-100) (385)

Measure 0 RTD (PT-100) (385)

Measure 100 RTD (PT-100) (385)

NLA-PT-C-P-31-01 Page 11 of 13 Date of Issue:

2017-10-05

2.2 SOURCE MODE FUNCTIONS

2.2.1 DC Voltage – Source mode

Fluke 744

Mode

Nominal Voltage

Fluke 744 Function

Measured Voltage

(V)

Measurement Uncertainty

(± V)

Source 5 V DC V

Source 12 V DC V

2.2.2 Frequency – Square Wave into > 1 MΩ input impedance - Source mode

Fluke 744

Mode

Nominal Frequency

(Hz)

Nominal

Voltage

(Vp-p)

Fluke 744 Function

Measured Frequency

(Hz)

Measurement Uncertainty

(± Hz)

Source 15 1 Hz

Source 20 000 1 Hz

NLA-PT-C-P-31-01 Page 12 of 13 Date of Issue:

2017-10-05

2.2.3 Resistance – Source mode

Fluke 744

Mode

Nominal Resistance

(Ω)

Fluke 744 Function

Measured Resistance

(Ω)

Measurement Uncertainty

(± Ω)

Source 100 Resistance (Ω)

Source 5 000 Resistance (Ω)

2.2.4 DC Current - Source mode

Fluke 744

Mode

Nominal Current

(mA)

Fluke 744 Function

Measured Current

(mA)

Measurement Uncertainty

(± mA)

Source 12 DC Current (mA)

Source 20 DC Current (mA)

NLA-PT-C-P-31-01 Page 13 of 13 Date of Issue:

2017-10-05

2.2.5 Thermocouple – Type K (ITS-90) – Source mode (simulating).

(Measure mV with external CJC at 0°C then look up appropriate temperature and record both mV and Temperature)

Fluke 744

Mode

Nominal Temperature

(°C)

Fluke 744 Function

Measured Voltage

(mV)

Measured/Table Temperature

(°C)

Measurement Uncertainty

(± °C)

Source -50 Thermocouple

Source 0 Thermocouple

Source 100 Thermocouple

Source 500 Thermocouple

2.2.6 PT-100 (385) Platinum Resistance Temperature Detector (RTD) (ITS-90) - Source mode (Measure resistance then look up appropriate temperature and record both resistance and temperature)

Fluke 744

Mode

Nominal Temperature

(°C)

Fluke 744 Function

Measured Resistance

(Ω)

Measured/Table Temperature

(°C)

Measurement Uncertainty

(°C)

Source 0 RTD (PT-100)(385)

Source 100 RTD (PT-100)(385)