Automation of test benches for electricity meters
Automation is dedicated for mass production of electricity meters.
The main goal of upgrade was to make all processes with static electricity meters in
in calibration and verification laboratory faster and simpler.
The test benches for electricity meters are developed by companies EMH (Germany)
and MTE (Switzerland). Automation described below was applied to 7 test benches.
Below you can see photos of test benches and their accessories.
Two stages of equipment upgrade were done.
Both upgrades (SW and HW) were accepted by Lithuanian National Accreditation Bureau and meets requirements of standard IEC 17025 for calibration laboratories.
1. New software "EMH Windows" was developed.
Software is able to handle up to 80 electricity meters at a time.
The main features of the software:
- Automated adjustment of static electricity meters (EMS, GEM, G3A, G1A, EPQS, EPQM, LZQM);
- Automated parameterisation of static electricity meters (EMS, GEM, G3A, G1A, EPQS, EPQM, LZQM);
- Calibration protocol for all types of electricity meters;
- Calibration protocol for internal watches of electricity meters (with internal watch);
- Additional functions for electricity meters.
2. Hardware modifying.
The goal of hardware modify was automated calibration of internal watch of electricity meters.
In normal operation of the test bench, output signal from reference meter is used for calculation percentage error of electricity meters.
Commutator was developed for possibility to choose which signal to use for error calculation - from reference meter or from GPS receiver.
Reference frequency 100kHz signal from GPS receiver can be commutated to test bench input.
This solution lets automatic adjust and calibrate internal watch of electricity meters.
Uncertainty of this measurement method is 0,04 [seconds / 24 hours].
Below you can see a photo of GPS receiver with reference frequency (100kHz) generator synchronised by signal from satellites:
