29-05-2024, 07:03 AM
This is my resistance meter, "Ohmmeter No.18 Mk2" or 18B
This unit runs from a battery and has two primary functions,
1) insulation test at 95 or 500 volts.
2) ohmmeter implemented by AC driven resistance bridge with two scale ranges
I have never found a manual or schematic for it but I think it is designed to check for leakage or to find the distance to a short on a phone line. It is branded with the Telecom 'T' logo
I have owned it for many years, somewhere I have instructions I devised for using it as a general purpose bridge for measuring arbitrary value resistance or capacitance by adding an external reference applied to two of the three terminals, the other two being the unknown component. I have a close tolerance 10nF cap with 4mm plugs on the end for this purpose. I must find the instructions I wrote, Ive put them somewhere safe, they were on a piece of card in the battery compartment.
It is capable of measuring very low resistances, I used to loan it out from time to time to be used to measure the resistance of high power AC bus bars.
The last time I used it was for checking the leakage on some old ceramic end TCC metalpack capacitors, they were perfect.
This unit runs from a battery and has two primary functions,
1) insulation test at 95 or 500 volts.
2) ohmmeter implemented by AC driven resistance bridge with two scale ranges
I have never found a manual or schematic for it but I think it is designed to check for leakage or to find the distance to a short on a phone line. It is branded with the Telecom 'T' logo
I have owned it for many years, somewhere I have instructions I devised for using it as a general purpose bridge for measuring arbitrary value resistance or capacitance by adding an external reference applied to two of the three terminals, the other two being the unknown component. I have a close tolerance 10nF cap with 4mm plugs on the end for this purpose. I must find the instructions I wrote, Ive put them somewhere safe, they were on a piece of card in the battery compartment.
It is capable of measuring very low resistances, I used to loan it out from time to time to be used to measure the resistance of high power AC bus bars.
The last time I used it was for checking the leakage on some old ceramic end TCC metalpack capacitors, they were perfect.
