Decades ago, when a customer found that my Tera Ohm Meter expensive, He suggested the specs for this low cost scaled-down model. This was found useful for people sub-contracting Telecom Equipment Manufacturing. Related Resources – Megger – Electric Power Test Equipment Megger-Wikipedia Megger instrument for measuring the insulation resistance High voltage ohmmeters Insulation Testers / Earth Tester Electrical Insulation Testing Products Insulation Resistance Tester
The one above was also made at TMPL, it is a Psophometer which was a true RMS auto-ranging AC dB level meter with weighted filters. The weighted filter has to resemble the audio response curve of the ear. With a built in signal generator in dB settings it becomes a Transmission Measuring Set. This was in the eighties, it is similar to this Transmission Measuring Set from Aplab, this was the only relevant link i got. I also remember that aplab also had submitted a sample of a bigger unit then. Then some nice European units also were being evaluated Read More …
Psophometer – Wikipedia, the free encyclopedia. I learnt some basic instrumentation when i worked on above Instrument, Mr. Ravi Rao the Manager in Trans Marketing Pvt. Ltd. gave that opportunity. TMPL as it was known decades back was in Service and Sales of many Brands like Racal Dana, Genrad, Data I/O and Electronic Production Machinery. Related Resources Digital Psophometer Model 1072 Automatic Loss Measurement Weighting filter ‘A’ Weighting Filter For Audio Measurements Programmable Universal Filter C-Message Weighting
Measurement Of Temperature – When power transistors are used, they may tend to over heat. Likewise resistors may also overheat in the event of faults or short-circuits. The knowledge of their temperatures may be advantageous. In addition, measurement of temperature constitutes a basic necessity in day-to-day life. Measuring the temperature of a body, depends upon the establishment of thermo-dynamic equilibrium between the body and the device used to sense the temperature. In practice, this condition is rarely attained since it is difficult to establish complete instantaneous equilibrium. Hence great care must be exercised in choosing a method suited to the Read More …
Measurement of Voltage : – In testing electronic circuits, Measurement of voltages is important for diagnosing faults and making the circuits work. In circuit diagrams given in equipment manuals, voltages at various points in the circuit are usually marked. A deviation from these values indicates that some component has failed and eventually leads to clues for isolating the faulty areas. Specifications :- D.C. Voltage Ranges : +/- 200 mV, 2V, 20V, 200V, 2000V. Input impedance: 10 mega ohms. Circuit protection: + 2000V D.C. all ranges. Over range: 100% to 1999. Accuracy: +/- 0.5%. A.C. Voltage Note: Average responding Ranges calibrated Read More …
I don’t remember if this circuit worked properly. But a few were made and i might not have shown the modifications that were done to make it work. This was meant to be a portable, low cost, insulation tester for an electrician. If you try it out and debug it it may work well. A negative voltage is derived by shifting gnd with two diodes, i feel this did not work very well. Two pins of CD4028 pins are also used to boost the reference to get two extra ranges as 4051 has a 100E on resistance. From Schematics of Read More …
Specifications Frequency range – 0.95 Hz to 105 KHz in five decade ranges Waveforms – Sine, Triangular and Square. Output amplitude – Adjustable from 10 mV PP. to 10 V PP Output impedance – 50 ohms. Datasheets ICL8038 waveform generator ICL8038 LM318 Operational Amplifier LM318 Circuits Electronics — ICL8038-based Oscillator Handy dandy little circuit #13 Glossary THD – Total Harmonic Distortion – Total harmonic distortion – Wikipedia, the free encyclopedia PP – Peak to Peak – RMS and peak – Peak-to-peak – Wikipedia, the free encyclopedia MFD – Micro Farad – Farad – Wikipedia, the free encyclopedia