Voltech PM100 this is UK England technology of the past (Year 1996).
Voltech PM100 this is an analog design of a digital power meter, and this translate at two essential details.
1) It can deliver accurate measurements, but of very few electrical parameters.
2) This analog design, uses a huge amount of electronic components, active and passive ones.
In the positive side of things, Voltech (not any more alive) it should be congratulated, for introducing the technology of huge in dimensions current shunt.
Voltech concept of using a huge in mass current shunt, this had significant benefits.
Back in time and when high precision current sense resistors was not an option, the use of a huge copper shunt in dimensions, this were delivering thermal stability and this helped measuring accuracy to be almost immune from sudden current variations.
Additionally this huge mass of copper, it was required and for a second reason, and this is shunt actual resistance it could be much lower.
The Asian competitor about instruments of this class of analog design this is HIOKI in Japan, they build the last high-end analog power meter, and this is the HIOKI 3332.
The analog design of a digital power meter, this has only one major issue, and this is power meter calibration / adjustment.
Calibration adjustment it should be made every few months.
Calibration adjustment this required lots of time and it was costly.
Since the year 2010 and later, Voltech's current shunt design were copied by Chinese makers of production line digital power meter.
The pile of analog components this is now replaced by low-end modern electronics, these delivering a sample rate of 8ks/S at best, and this technology are sold in the domestic market of China for about 60 ~ 100 $ USD.
Analog design of a digital power meter , this is unable to compete when fast sampling required, for example about the measurement of inrush current, and or at Non-linear loads in which the current this is not stable, as is at resistive loads.
This train does not turn back, such analog instruments were designed for AC loads of another era, as is resistive loads and copper based transformers, and or Lighting Ballast this be the most high end application of that era.
Bellow are few photographs, of Voltech PM100, you may admire the world of analog design of a digital power meter, and the product design of a huge shunt.