On January 2019 ICE (Instituto Costarricense de Electricidad) and The National Institute of Standards and Technology (NIST) completed the process of inter-comparison of high resistance values, which aimed at comparing the measurement capabilities of ICE-LMVE and NIST in order to establish the degree of equivalence between the two laboratories.

During 2018, two resistance standards were used as traveling standards for measurements in those countries, with NIST-USA acting as the pilot laboratory for the SIM.EM-S15 comparison. NIST used a NIST designed 100 MΩ guarded Hamon transfer standard resistor and a 100 GΩ guarded Hamon transfer standard resistor as reference standards for the measurements. A direct substitution was used to calibrate the traveling standards, and measurements were taken on the traveling standards at both institutes.

The NIST resistance standards were measured at NIST at the beginning and end of the comparison schedule, and later travelled to the ICE laboratory. ICE calibrated both resistors and sent the results back to the NIST.

Participants measured the 100 MΩ at 10 V and 100 V; and the 100 GΩ at 100 V and 500 V; both values presented at 23 °C. All resistance measurements with corresponding combined standard uncertainties were reported, and at least four measurements over three days for each voltage were done.

 Countries and Institutions

Organization of the American States (OAS) National Institute of Standards and Technology (NIST)