Category: Blog

Vintage Measurement Equipment

80 Years of Instrumentation Innovation

This year Weschler Instruments celebrates its 80th year as a supplier of meters and instrumentation. Much has changed in electronic measurement equipment and technology since 1941. Vacuum tubes were replaced by transistors and then integrated circuits. Analog indicators became digital readouts and then graphical touchscreens. Manual operation migrated to automatic sequencing and then fully computerized tests. (more...)

Temp Transmitters

Temperature Measuring Instrumentation

The Weschler Temperature Measurement application note reviews the characteristics of popular sensors used to measure temperature: thermocouple, RTD (resistance temperature detector), thermistor, semiconductor, and infrared. This article surveys the instrumentation used in conjunction with these sensors for industrial temperature measurements. (more...)

3 channels power supply

4-20 mA Loop Instrumentation

Three devices are needed to make a 4-20 mA current loop – a transmitter, receiver and loop power supply. (more...)

Basic 4-20 mA Current Loops

Basic 4-20 mA Current Loops

The current loop is a widely used industrial control circuit topology. The basic current loop has three elements:

  • A transmitter that sends a dc current around the loop
  • A receiver that measures the current in the loop
  • DC voltage supply that powers the loop
  • (more...)
DC Current Shunts

Using DC Current Shunts

A DC current shunt is a specialized resistor used to measure high currents. The shunt is wired in series with a heavy load, such as a DC motor, battery charger, heater, plating bath or smelter pot line. A DC voltmeter is connected to the shunt in a 4-wire (Kelvin) configuration. (more...)