Form "A" (Normally Open)
Switch contacts will close in the presence of a magnetic field.

Form "C" (Single Pole, Double Throw)
Form "C" switches have transfer mode contacts.
When a magnetic field is applied, the common contact will be transferred from the normally closed (N.C.) contact to the normally open (N.O.) contact.

Rhodium
Rhodium plated contacts are most popular. They have very stable characteristics and long life when switching low level to heavy loads. This is due to Rhodium's high melting point and high hardness.

Ruthenium
Ruthenium's hardness is even greater than that of Rhodium. Ruthenium contacts have better mechanical wear and heat dissipation characteristics, yet only when switching low loads.
Because of these characteristics ALEPH has developed a double plated contact with Ruthenium Oxide over Rhodium or Palladium. These double plated contacts have very good switching characteristics from low level to heavy loads.

Mercury Wetted
Mercury wetted reed switches feature bounceless operation, and therefore do not require additional bounce inhibiting circuitry. They have high power switching capability, low and stable contact resistance characteristics, and long life. They may also be used for high inrush current switching.

Application Notes:

1. When load conditions induce arcing, mercury may evaporate from the contact area. This may cause contact welding. Therefore, these switches should not be used in applications where arcing cannot be controlled.
2. Mercury wetted switches must be operated only within +/- 30 degrees from vertical.