Test Coils for Reed Switches and Reed Sensors
Features
Wound on Wooden Bobbin. Enamelled Copper Windings. Uniform Layering. Accurate Coil resistance.
Benefits
Withstands 80°C. Economical Repeatable Measurements. Suitable for 4-Terminal Kelvin Circuits. Suitable for Reed Switch Life Tests.
Description
Using Test Coils is one of the most accurate ways of measuring various parameters of a Reed Switch, Reed Sensor or Magnet Sensor, such as Operate AT, Release AT, Contact Resistance and other test parameters. The number of turns in the coil multiplied by the current at which the switch closed gives the Operate Ampere Turn, which is a direct measure of its magnetic sensitivity.
Care should be taken to see the the coil is always used vertically so that the earth’s magnetic field does not affect the measurement, and that the reed switch or reed sensor under measurement is always centered inside. No Ferro-magnetic crocodile clips, connectors or mounting parts should be nearby as this will cause measurement errors. It is always more accurate to use Four-terminal Kelvin measurements.
We offer customers a range of Test Coils, in cylindrical and rectangular shapes, to suit the measurement of our products. The Test Coil specifications are listed below.
Cylincdrical Test Coil Dimensions
| Test Coil Code | 001 | 002 | 003 | 005 | |
|---|---|---|---|---|---|
| Bobbin Length (BL) | mm | 53.5 | 21.0 | 12.0 | 19.0 |
| Winding Length (WL) | mm | 50.8 | 19.0 | 10.0 | 15.0 |
| Flange Outer Diameter (FOD) | mm | 14.1 | 7.7 | 11.0 | 11.0 |
| Flange Inner Diameter (FID) | mm | 5.6 | 3.4 | 2.3 | 2.9 |
| Copper Wire Diameter | mm | 0.090 | 0.050 | 0.060 | 0.071 |
| Coil Resistance | Ω | 845 | 740 | 600 | 450 |
| Turns | 10000 | 5000 | 5000 | 5000 |
Rectangular Test Coil Dimensions
| Test Coil Code | 3001 | 3002 | 3003 | 3004 | |
|---|---|---|---|---|---|
| Bobbin Length (BL) | mm | 13.5 | 23.3 | 42.5 | 42.5 |
| Winding Length (WL) | mm | 7.0 | 19.7 | 36.5 | 36.5 |
| Flange Outer Length (FOL) | mm | 18.0 | 20.6 | 28.6 | 35.6 |
| Flange Inner Length (FIL) | mm | 10.0 | 11.6 | 13.6 | 20.8 |
| Flange Outer Width (FOW) | mm | 14.0 | 14.8 | 25.0 | 25.0 |
| Flange Inner Width (FIW) | mm | 6.0 | 6.2 | 13.8 | 13.8 |
| Copper Wire Diameter | mm | 0.05 | 0.08 | 0.15 | 0.15 |
| Coil Resistance | Ω | 2000 | 1900 | 290 | 440 |
| Turns | 5000 | 10000 | 5000 | 5000 |
Related Links
Reed Switch Life Tests
 |
A reed switch life test is a destructive test conducted to ensure the reliability of reed switches for different combinations of voltage,
Continue reading
Sep 5, 2019 |
Reed Switch Test Procedure
 |
When taking measurements, care should be taken that the Test Coil and the Reed Switch are vertical, or if horizontal, only in an east-west
Continue reading
Nov 11, 2020 |