A meter relay is a meter with a switched output that can be used to control a process or activate an alarm. In its simplest form, an analog meter relay uses mechanical contacts or a microswitch to operate an external device when the analog meter pointer reaches the level of the set pointer. (more...)
80 Years of Panel Meter Evolution
When Weschler started in 1941, panel meters were hand-made analog instruments. The typical meter had either a metal or bakelite case, a glass lens and an electro-mechanical movement. There were many US manufacturers during the 1940s and 1950s, including Triplett, Simpson, Weston, GE, Westinghouse, Beede, Hoyt, Hickok, Jewell, Marion, Supreme, (more...)
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...)
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...)
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...)