SIM Bilateral CENAMEP AIP - INTN
50/60 Hz Energy Comparison Protocol
2015
1 Introduction
The Mutual Recognition Arrangement (MRA) among National Metrology Institutes
(NMIs) places particular importance on comparisons to demonstrate a NMI’s ability
to measure certain quantities.
Reliable measurements of electric energy are the cornerstone of electric
restructuring schemes in economies worldwide. Any opportunity of testing the
reliability of measuring methods and reference standards at an international level is
very valuable to national metrology institutes.
The comparison objective will be to compare the electric energy measurement
capabilities of the Centro Nacional de Metrología de Panamá (CENAMEP AIP) and
the Instituto Nacional de Tecnología, Normalización y Metrología de Paraguay
(INTN).
These INMs decided to perform the comparison at 50 and 60 hertz. Three points
were selected to test the amplitude and phase measuring capabilities of the NMIs:
120 volts and 5 amperes at power factors 1.0, 0.5 lead (ld), 0.5 lag (lg), where lead
(capacitive) indicates that the current leads the voltage and where lag (inductive)
indicates that the current lags the voltage.
2 Traveling Standard
2.1 General requirements
The traveling standard, the RD-23-433 is designed and built by Radian Research
Inc.
The RD-23-433 Dytronic Single-Phase Reference Standard aims at providing a
worst case accuracy of ± 0.01 % for all measurements functions. It is well suited for
making transfer measurements of energy.
2.2 Description of the standard
The RD-23-433:
Serial number: 20 54 59
Size: 190.5 mm (height); 139.7 mm (wide); 139.7 mm (deep), excluding strap
Weight: RD-23-433 = 2.5 kg (total transport container = 10.5 kg)
Potential inputs: insulated 4 mm multi-contact brand sockets
Current input: 6 mm multi-contact brand sockets. 3 input current channels area
available, being channel A which must be used for this comparison.
Auxiliary input: insulated 4 mm multi-contact brand sockets
Input/gating: port 1, BNC connector
Output pulse: port 2; BNC connector, to be used for energy measurements only.
Three phase SYNC or analog sense: port 3; BNC connector
RS-232 communication: a 8 pin RJ-45 jack
Operating rate of the RD-23-433
Input current: 0.2 to 67 A
Input voltage: 30 V to 630 V, autoranging
Frequency: 45 Hz to 75 Hz (fundamental)
Auxiliary power input: 60 V to 630 V, autoranging
Phase angle: 0° to 360 °
Power factor: 1 to 0 lead, lag
Temperature: 20°C to 30 °C
Humidity: 0% to 95% non-condensing.
2.3 Quantities to be measured
The calibration error of the traveling standard for energy measurements
1. The result to be reported is the calibration error of the traveling standard,
defined as the difference between the measured quantity indicated by the
traveling standard and the quantity applied to it, and divided by the applied
VAh. The calibration error should be expressed in ± μWh/VAh. The error is
positive if the traveling standard's indication is more positive than the
applied quantity.
2. The average of at least five sets of measurements should be reported. The
traveling standard should be de-energized between each set of
measurements for at least one hour, followed by at least one hour warm-up
period.
3. The total estimated expanded uncertainty quoted in the report encompasses
the Type A uncertainty and the Type B uncertainty of the corresponding NMI
calibration system. The expanded uncertainty should be estimated for a
level of confidence of 95.45 %.
Table 1. Test points of SIM.EM-XX
Parameter
RMS voltage
RMS current
Power Factor
frequency
Energy [Wh]
120 V
5A
1.0
0.5 lead-lag
50 and 60 Hz
2.4 Method of computation of the Bilateral Comparison Reference Value
The declared values by CENAMEP AIP will be used as the Bilateral Comparison
Reference, for being this NMI the responsible for realize the metrological
characterization of the traveling standard.
3 Organization
The Centro Nacional de Metrología de Panamá (CENAMEP AIP) will be the pilot
laboratory. The traveling standards will begin at CENAMEP AIP.
3.1 Coordinator and members of the review committee group
Coordinators and contact persons of the pilot laboratory:
Julio González (CENAMEP AIP) jgonzalez@cenamep.org.pa
Carlos Espinosa (CENAMEP AIP) cespinosa@cenamep.org.pa
Organization: Centro Nacional de Metrologia de Panamá (CENAMEP AIP).
Address: Edificio 215, Ciudad del Saber, Clayton, Ciudad de Panamá, Panamá.
Phone: +507 517 3131. Fax: +507 517 3200.
Members of the review committee group:
Julio González (CENAMEP AIP) jgonzalez@cenamep.org.pa
Carlos Espinosa (CENAMEP AIP) cespinosa@cenamep.org.pa
Jorge Parra (INTN) jparra@intn.gov.py
3.2 Participants
Centro Nacional de Metrología de Panamá (CENAMEP AIP) **
Instituto Nacional de Tecnología, Normalización y Metrología de Paraguay (INTN).
** This laboratory participated in SIM.EM- S2 and SIM.EM-S7, both 50/60 Hz Energy Comparisons
Criteria for participation in the comparison include the availability of adequate
trained staff and high-level measurement apparatus and procedures. It is important
that personnel in each participating NMI will be available to complete the
comparisons within the scheduled time window. If, for some reason, the
measurement facility is not ready or custom clearance should take too much time,
the laboratory is requested to contact immediately the pilot laboratory.
3.3 Time Schedule
A period of four weeks is allowed for the measurements in each laboratory,
including the time necessary for transportation. The CENAMEP AIP, will make
measurements before and after the measurements realized by INTN.
3.4 Transportation
The traveling standard will be hand carried from one laboratory to another by a
technician of CENAMEP AIP.
The RD-23-433 will be provided with a rugged plastic container, suitable for
transported the standard on airplane.
The standard will be packaged along with a temperature/humidity logger. During
measurements at the participant’s laboratory, make sure that the logger remains
on the top surface of the traveling standard, mainly close to the backlit LCD of the
traveling standard, in order to log measurements of ambient temperature and
humidity. There is no need for the participating laboratory trying to gain access to
the logger; its contents will be downloaded at CENAMEP AIP in order to keep track
of the changes of temperature or humidity during transportation or while staying at
the participating laboratory.
On receipt of the standard, the participant shall inform the pilot laboratory by
sending an email notifying the reception. Then it should receive a reply
(confirmation) e-mail from the pilot lab.
3.5 Shipping and Handling
The traveling standard will be hand carried from one laboratory to another by a
technician of the pilot Laboratory.
The transport case contains the following items:
Parts List
1. (1) The RD-23-433 Dytronic Single-Phase Reference Standard.
2. (1) 120 VAC Auxiliary Power input cable for RD-23-433.
3. (2) Converts the standard 4 mm banana plug to 6 mm current inputs on
RD-23-433.
4. Temperature and humidity data logger.
3.6 Failure of the traveling standard
In case of failure:
1. Unplug the traveling standard.
2. Write immediately to the pilot laboratory describing the behavior of the traveling
standard. Send along any message displayed on the backlit LCD. Take
photographs of the measuring system and of the connecting cables to the
traveling standard.
3. Wait for instructions from the pilot laboratory on the way to proceed.
3.7 Financial aspects, insurance
The traveling standard will be provided by CENAMEP AIP.
INTN covers the costs of the shipment, transportation and customs clearance.
4 Measurement instructions
4.1 Tests before measurements
1. There are no tests on the RD-23-433 traveling standards to be performed
before measurements at the participant’s laboratory.
2. Energizing the traveling standard. The auxiliary power to the traveling
standard should be applied at least 4 hours before starting the tests:
Note: In order to achieve the best measurement capability of the
traveling standard. The RD-23-433, once the standard has been
allowed to warm up at least 4 hours at room temperature, the
participant must turn down and on the standards. This action will set
the internal references of the standard corrected at their internal
temperature.
4.2 Measurement performance
1. Perform the tests within 2 weeks, taking as many independent readings of
the traveling standard as stated in the calibration procedures of the
laboratory.
2. The traveling standard should be de-energized at least two times during the
tests. Allow at least 4 fours of de-energizing time before energizing the
traveling standard again.
3. Report the date and time when the traveling standard is de-energized and
energized.
Particular requirements for connecting the traveling standard.
Figure 1. Connecting the RD-23-433.
NOTE: for the measurement of current when using the RD-23-433, use
Input Terminal A, as shown in Photo 1.
Photo 2. RD-23-433
4.3 Method of measurements
Recommended method: The comparison of electric pulses.
The traveling standard is an energy meter of the energy-to-pulse converting type.
The energy constant, KH, of this standard is equal to 100 000 pulses/Wh.
At 120 V, 5 A and power factor equal to unit, RD-23-433 are able to generate a
train of pulses with a frequency equal to 16 666.66 pulses per second.
1. for the voltage and current sources, make sure that their frequency is set at
50 or 60 Hz, according to the testing points shown in Table 1;
2. at every testing point shown in Table 1, make as many independent
measurements of the calibration error of the traveling standard as stated on
the calibration procedures of the laboratory;
3. Complete the calibration of the traveling standard by obtaining the mean
value of its calibration error obtained at the testing points shown in Table 1.
The calibration error is defined as the difference between the measured
quantity indicated by the traveling standard and the quantity applied to it,
and divided by the applied quantity. The calibration error of the traveling
standard should be expressed in μWh/VAh.
4. the number of pulses on the RD-23-433 should be set to 1 000 000 (one
Million);
5. for 1 million pulses, the integration time Ti for energy measurements will be
approximately equal to:
a. Ti = 60 seconds, at 120 V / 5A / pf = unit;
b. Ti = 120 seconds, at 120 V / 5 A / pf = 0.5 lead-lag.
6. the average of at least four sets of measurements should be reported;
7. the traveling standard should be de-energized between each set of
measurements for at least one hour, followed by at least one hour warm-up
period;
8. the total estimated expanded uncertainty quoted in the report encompasses
the Type A uncertainty and the Type B uncertainty of the corresponding NMI
calibration system. The expanded uncertainty should be estimated for a
level of confidence of 95.45 %.
9. report the mean value of the ambient temperature and relative humidity of
the laboratory;
10. the measurement report of the participant may be completed according to
Annex A2 Layoutof the measurement report
5 Measurement results and uncertainty
The uncertainty of measurement must be determined following the Guide for the
Expression of Uncertainty in Measurement [3].
Participant laboratories are requested to report the main uncertainty components of
their measurement systems, identifying all the pertinent uncertainty sources and
quantifying their contribution to the expanded uncertainty.
In order to have a comparable uncertainty evaluation, each laboratory is asked to
report the following information in the form of an uncertainty budget:
1. The result of the type A method of uncertainty estimation which yields the
standard deviation of the mean values of data sets recorded by the
participant in order to calculate its final report value.
2. The result of the type B method of uncertainty estimation.
3. The expanded uncertainty estimated at a 95.45 % level of confidence.
4. The degrees of freedom for the estimation of the expanded uncertainty at a
95.45 % level of confidence.
A suggested format for the uncertainty budget is given:
Main Uncertainty Components
(yi)
Standard
Uncertainty
u(yi)
Type method A or B of Sensitivity
Degrees of
Uncertainty
evaluation/probability coefficient
freedom
contribution u(Ri)
distribution function
Ci
ni
Desviation of the readings of
traveling standard
µWh/VAh
µWh/VAh
Standard calibration uncertainty
µWh/VAh
µWh/VAh
Resolution of Standard
µWh/VAh
µWh/VAh
Drift of Standard
µWh/VAh
µWh/VAh
Standard temperature coefficient
µWh/VAh
µWh/VAh
Root square sum of type A standard uncertainties and effective degrees of freedom
µWh/VAh
Root square sum of type B standard uncertainties and effective degrees of freedom
µWh/VAh
Combined standard uncertainty and effective degrees of freedom
µWh/VAh
Expanded uncertainty (95.45% coverage factor)
µWh/VAh
6 Measurement report
The participant laboratory should report the following information within 4 (four)
weeks from the end of measurements:
a) The mean of the calibration error of the traveling standard. The calibration
error should be relative and expressed in terms of ± μWh/VAh.
b) The expanded uncertainty of the error of calibration of the traveling standard
at 95.45 % level of confidence. It must be expressed in terms of ± μWh/VAh.
c) The uncertainty components coming out from the Type A and B methods of
uncertainty estimation of the calibration error of the traveling standard.
d) The expanded uncertainty of the calibration error of the traveling standard
should be determined at a 95.45 % level of confidence.
e) Measurement uncertainties shall comply with the Guide to the Expression of
Uncertainty in Measurement [3].
f) According to the calibration procedures of the participant laboratory, the
mean values of ambient temperature and relative humidity should be
reported.
g) A complete uncertainty budget and any additional information must be
reported as shown in Annex A3.
The participant must submit their results of the comparison to the pilot laboratory
(jgonzalez@cenamep.org.pa; cespinosa@cenamep.org.pa), as soon as possible,
in every case, not later than 4 (four) weeks after the measurements are completed.
Drafts A and B will be the responsibility of the review committee, following the
BIPM guidelines.
7. REFERENCES
1. Rene Carranza, SIM.EM.-S7 Technical Protocol, SIM Supplementary
Comparison of 50/60 Hz Energy BIPM 2010-2011.
2. CCEM Guidelines for Planning, Organizing, Conducting and Reporting
Key, Supplementary and Pilot Comparisons. CCEM, 21 March 2007.
3. Evaluation of measurement data – Guide to the expression of uncertainty
in measurement, BIPM JCGM 100:2008.
Annex A1
List of participants
Organization
Country
Contact Person
Julio González
CENAMEP
AIP
Panamá
INTN
Paraguay
Carlos Espinosa
Jorge Parra
E-mail
jgonzalez@cenamep.org.pa
cespinosa@cenamep.org.pa
jparra@intn.gov.py
Annex A2
Layout of the measurement report
1. Identification of the traveling standard: RD-23-433
2. Identification of the participant laboratory and its representative
3. Measurement set-up and traceability scheme
4. Measurement procedure
5. Results:
a) Mean value of the calibration error of traveling standard at the testing points
shown in Table 1, expressed in ± μWh/VAh.
b) Expanded uncertainty estimated at a 95.45 % confidence level and the
degrees of freedom of the calibration error of the traveling standard.
c) Mean date of measurement.
d) Ambient conditions: mean value and spread of temperature and humidity
measurements.
6. Detailed uncertainty budget (view the point 5 of protocol)
7. Report the date and time when the traveling standard is de-energized and
energized.
8. Signature and title of the laboratory representative.