EDI Model SM Magnetic Switch System consists of a sealed reed switch for use in above and below ground test stations. The switch is activated by holding a magnet next to it.

Typical Applications:
Cathodic protection coupons – use a normally-closed switch to simplify making instant-disconnect measurements.
Reference electrodes – use a normally-open switch to keep the reference electrode isolated from the structure except when measurements are being made.

Electrical Specifications

Switching Current: 0.5 amps
Carry current: 1.0 amp
Switching Voltage: 175 volts
Breakdown voltage: min. 200 VDC
Contact resistance: 150 mohm
Operating temp.: -40°F – 260°F (-40°C – 130°C)

Switch Configurations

Board Mount: switch is mounted on a small circuit board with two 9/32 in. (7 mm) dia holes on a 1 in. (25.4 mm) spacing.
Specify as Model SM-BRD-x

Adjustable mount: switch is centered in a length of wire terminating in 9/32 in. (7 mm) ID ring lugs. Ring lugs are spaced at 6-1/4 in. (160 mm).
Specify as Model SM-ADJ-x

Note – x refers to switch type:
C = normally closed, use magnet to open (green band)
O = normally open, use magnet to close (red band)

Activating Magnet

Specify as EDI Model SM-MAG

Magnetically operated switches are momentary toggle switches which are activated by touching the magnet to the color band on the switch body. Green bands denote normally closed switches which are momentarily opened with the magnet. These are most often used for instant-disconnect cathodic protection coupon measurements. Red bands denote normally open switches which are momentarily closed with the magnet. These can be used to electrically isolate a reference electrode in test stations which may become submerged.

For best results, the use of Model SM-MAG magnets are recommended.