Japan Electrical Meters Inspection Corporation

Minato-ku, Japan

Japan Electrical Meters Inspection Corporation

Minato-ku, Japan
SEARCH FILTERS
Time filter
Source Type

Kodaira K.,Japan Electrical Meters Inspection Corporation
IEEJ Transactions on Fundamentals and Materials | Year: 2012

An evaluation method of platinum resistance thermometers (PRTs) used in the stationary air was considered. A comparison measurement apparatus to evaluate PRTs was developed by using a commercially available temperature bath and the performance of the apparatus was evaluated. The apparatus has high temperature stability and good temperature distribution although the thermal medium is the air. The uncertainty of the apparatus is less than 1 mK. A PRT was evaluated for a trial with this apparatus at 23 °C. First, a PRT that was set in the water was measured with a Standard Platinum Resistance Thermometer (SPRT) in the temperature bath. Next, the identical PRT was set in the air chamber of the developed apparatus and measured with the SPRT. And, each result was compared. As a result, it was possible to distinguish the difference of behavior of the PRT at different environment by a proposed method in this study. And, it was confirmed that the cause of different behavior was the self-heating of the PRT. © 2012 The Institute of Electrical Engineers of Japan.


Kawagoe J.,Japan Electrical Meters Inspection Corporation | Kawasaki T.,Japan Electrical Meters Inspection Corporation
IEEE Transactions on Instrumentation and Measurement | Year: 2010

A digital phase meter (DPM) for power frequencies with a very low measurement uncertainty of 1 μ rad was developed at Japan Electric Meters Inspection Corporation (JEMIC) to establish a power and energy calibration system. We also developed a phase meter calibrator (PMC) for calibrating the DPM. Since the DPM and PMC are synchronized with a single clock, the DPM can be calibrated by a very simple measurement method, which no longer requires extra standards. The DPM has been employed as an instrument for the primary standard of power and energy in Japan to achieve precise phase angle measurement. Since the error in the power measurement at power factor 0 is equal to the error in the phase angle measurement, we verified the performance of the DPM by calibrating a standard power meter using the power calibrators at JEMIC and Physikalische-Technische Bundesanstalt (PTB), and comparing the test results at power factor 0. According to the measurement, the phase angle difference between JEMIC and PTB is within 7 μrad. © 2006 IEEE.


Takahashi K.,Japan Electrical Meters Inspection Corporation | Yamawaki M.,Japan Electrical Meters Inspection Corporation | Tadokoro T.,Japan Electrical Meters Inspection Corporation
IEEE Transactions on Instrumentation and Measurement | Year: 2013

This paper describes a method to calibrate high current (20 kA) transformers, using a current comparator with a maximum test current of 100 A as a primary standard. In order to fill the large gap in the test current between 20 kA and 100 A, two novel techniques are developed, i.e., 1) the current-ratio transfer standard (CRTS), and 2) the improved equivalent ampere-turn method. The CRTS is a two-stage current transformer with two selectable current ratios of 500A/5A and 100A/5A. The two ratios are realized by the selection of parallel or series combination in the primary windings of the CRTS. The design and the performance of the 100-A primary standard, a coaxial-type self-calibratable current comparator, is also described. © 2013 IEEE.


Takahashi K.,Japan Electrical Meters Inspection Corporation | Yamawaki M.,Japan Electrical Meters Inspection Corporation | Tadokoro T.,Japan Electrical Meters Inspection Corporation
CPEM Digest (Conference on Precision Electromagnetic Measurements) | Year: 2012

To calibrate a Current Transformer CT, the Current Comparator CC must be most reliable standard [1][2]. However, it is difficult to assembling CC or estimating errors at high current. Meanwhile, there were some chances to test a high-current CT that exceeds a current limit of the existing traceable standard. The widely known parameter measurement should be a possible approach to prepare CT as a working standard. This paper proposed an improved parameter measurement and presented sample data for a window type CT WS whose nominal current is 20 kA. © 2012 IEEE.


Goto T.,Japan Electrical Meters Inspection Corporation
20th IMEKO World Congress 2012 | Year: 2012

In the case of calibration of direct acting indicating analogue electrical measuring instruments (hereinafter called the "analogue instruments"), uncertainty budget largely depends on dispersion of readings for scales through a needle. This paper describes experimental results for three levels of voltage (10 V, 6 V, and 3 V) of analogue instruments. In the experiments, two way layout nested design was introduced for each voltage level. From the results of present experiments, it was revealed that expanded uncertainties obtained were about 1/3 for the specification that obtained from the past experience.


Abe T.,Japan Electrical Meters Inspection Corporation | Imai H.,Japan Electrical Meters Inspection Corporation
20th IMEKO World Congress 2012 | Year: 2012

As for the evaluation of uncertainty in calibration of 100 MΩ standard resistor in Japan Electric Meters Inspection Corporation (JEMIC), the number of repetition of measurement is small, so the variation of measurement dominant and coverage factor becomes 2 or more. The result which was examined concerning the uncertainty evaluation method is reported in this paper.


Kato H.,Japan Electrical Meters Inspection Corporation | Imai H.,Japan Electrical Meters Inspection Corporation
20th IMEKO World Congress 2012 | Year: 2012

Japan Electric Meters Inspection Corporation (JEMIC) is a Designated Institute of power and energy standards in Japan. All the energy meters for electricity trading in Japan are traceable to the National Standard in JEMIC. In industrial world, power is supplied by various voltage and current. However, the energy standard has been calibrated at 110 V and 100 V, for 5 A. Therefore, it is often used in combine with the instrument transformer. This paper describes the effect of composite error of instrument transformers to uncertainty evaluation of energy meters.


Tsutsumi S.,Japan Electrical Meters Inspection Corporation
Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi) | Year: 2014

Inductive voltage dividers (IVDs) are widely used in the field of ac measurements, such as impedance measurements at audio frequencies. The two-stage guarded IVD was developed by D.N. Homan and T.L. Zapf about 40 years ago. However, it is not easy to construct a two-stage guarded IVD. Therefore, we have developed a two-stage IVD using a special winding method without guarding by magnetic and electrical shields. To reduce the admittances of the winding wires, corrugated polypropylene board is used for the new two-stage IVD. In addition, the ratio winding and excitation winding are wound toroidally around two FINEMET ring cores using PEW flat cable 0.7 mm in diameter. As a result, the in-phase ratio errors are within ±6.1×10-8 of the input at frequencies of 1 kHz or below. In this report, the winding methods and measurement results of the new two-stage IVD are described. © 2014 Wiley Periodicals, Inc.


Sato H.,Japan Electrical Meters Inspection Corporation
AIP Conference Proceedings | Year: 2013

According to the IEC standard 60751 Ed.2 (2008), the stability of the resistance value of platinum resistance thermometers (Pt100) should be less than the declared tolerance value after a minimum of 672 hours maintained at the upper temperature limit. However, the most important requirement for thermometers to use as a working standard is whether the resistance value will be stabilized or not after 672 hours annealing. We carried out stability tests of 15 thermometers at 450 °C over 1000 hours to confirm that these products are capable to use as temperature standards in our laboratory. And the result of additional experiments show that pre-annealing process before fabrication of a thermometer is able to improve stability. © 2013 AIP Publishing LLC.


Sato H.,Japan Electrical Meters Inspection Corporation
Proceedings of the SICE Annual Conference | Year: 2012

Industrial Platinum Resistance Thermometer (IPRT) is a temperature sensor makes use of relationship between resistances of a platinum sensing element and temperatures. IPRT is widely used in industry, research and developing fields due to its high reliability. In precision measurements, AC bridges or high resolution digital instruments which can reverse the polarity of measurement current are used to eliminate parasitic electromagnetic-force (EMF) produced at somewhere in a metal-sheath of IPRT. On the other hand, low-cost digital instruments which cannot reverse the polarity are using in some applications. It should be noted that the readout temperatures from such instruments may be affected by parasitic EMF depending on measurement conditions. In some cases, the magnitude of temperature affected by parasitic EMF may be beyond calibration uncertainty. This problem has not been focused in the past. The results of measurements using 10 IPRTs are reported. © 2012 SICE.

Loading Japan Electrical Meters Inspection Corporation collaborators
Loading Japan Electrical Meters Inspection Corporation collaborators