Current loop panel readout devices
If you’re still using moving-needle analog panel meters, Otek offers more modern alternatives that don’t require external powering.
Companies that are still using analog panel meters as displays with 4-20 mA instruments can replace those legacy devices with a readout that does not require external powering. Otek’s LPD series bar meters offer tri-color LEDs in straight-line or circular arrangements along with numerical values.
Some models can be inserted in the same circuit as an analog meter with no wiring modifications. Others in the larger Otek product line that are externally powered can send loop power to the field device or send process data on to a larger control system.
Otek says these new options are available due to advances in consumer electronics. “Handheld technologies have created a demand for ultra-low-power microprocessors,” says Dr. Otto Fest, president of Otek. “LEDs are made continually better and brighter. Integrated circuits are designed to run faster and at lower voltages. These advances have reached a point where robust digital instrumentation can work interchangeably with old analog meters, powered simply by the current loop. Brighter, color-changing displays, several digits of precision, DCS/SCADA interfacing, you name it—the benefits of a digital control panel don't have to be a nightmare to realize.”
Edited by Peter Welander, pwelander(at)cfemedia.com