ID:
2279
Maker's Name:
Weston Electrical Instruments Corp.
Where made:
USA
Dimensions:
13.3 × 2.6 × 3.3 cm
This unit contains a heating element and thermo junction for a thermo ammeter. The current rating of the unit is 20 Amps.
Thermo ammeters were commonly used as they had a wide frequency range of use, from DC to radio frequencies.
They have a slow thermal response so were unsuitable for observing rapid changes in current in a circuit, such as speech waveforms.