MODEL 7OB RESISTANCE SENSING POWER RELAYS
MODEL 7OB RESISTANCE SENSING POWER RELAYS
- For precision control of resistance-type transducers . . . such as RTD’s, thermistors, pressure sensors, strain gages, etc.
- Ten models cover all resistance ranges between 1 ohm and 95k ohms.
- Adjustable trip point can be set to O.5% accuracy.
- Available with or without electromechanical power relay or with solid-state power relay.
OPERATION IS SIMPLE
The 70B series Resistance Sensing Power Relay are control device operated by any resistance-type transducer such as a resistance temperature detector, thermistor, strain gage, pressure transducer, accelerometer. photo cell, position indicator, or others. Any resistance-type transducer with an operating point or range between 1 ohm and 93K ohms can he used with one of the ten models which cover this range in overlapping increments. The device operates as a set-point relay; that is, it may be adjusted to trip at any pre-determined resistance.
TYPICAL APPLICATIONS
For example, a resistance temperature detector (RTD) may be connected to a Resistance Sensing Power Relay and adjusted to trip at a certain temperature; or a pressure sensor to trip at a desired pressure; etc. Its operation can be normal (switching circuit de-energized in non-operating condition), or “failsafe” (switching circuit energized in non-operating condition).
SPECIAL FEATURES
The ten models are each adjustable within their individual ranges by either a ten-turn pot with calibrated dial, or a ten-turn pot with screwdriver adjustment, options that are available at the time of ordering. You also have the option of ordering with or without an electro-mechanical power relay, or with a solid-state power relay for conventional switching of any load or “zerovoltage” switching of resistive loads.
HIGH ACCURACY
Like any other adjustable device, accuracy will depend upon the care used in its connection and adjustment. Using only the calibrated dial to visually adjust the set point, an accuracy of better than ±8% can be obtained. Using a known resistance to aid in the set-point adjustment, accuracies of 0.5% for the ten-turn dial may he obtained. Once set, all models will provide a repeatability of ±0.5%.
EASY TO USE
Resistance Sensing Power Relays are completely solid-state and have no moving parts except the electro-mechanical power relay if specified. The resistance sensing input circuit is isolated from other circuitry and operates with less than 16 volts on the electrodes. They are easy to use, accurate, dependable. and universal in application. See the following 2 pages for additional information.
POWER REQUIREMENTS: All standard models are for 115 VAC, 50/60 cps, single phase, less than 10 VA. Other line voltages and/or frequencies are available on special order at additional cost.
AMBIENT TEMPERATURE RANGE: 0 to +140º F.
