5.1 Requests of mechanical and physical parameters:

   To Guarantee the mounting dimension, weight, hermetisation, the intensity and soldering of the terminals etc.,mechanical parameters mainly include contact force, contact gap, contact follow, return spring force, armature travel, stop plate height etc.

5.1 Requests of mechanical and physical parameters:

   To Guarantee the mounting dimension, weight, hermetisation, the intensity and soldering of the terminals etc.,mechanical parameters mainly include contact force, contact gap, contact follow, return spring force, armature travel, stop plate height etc.

5.3 Requests of time parameters:

   When controlling the circuits, pickup and dropout time is usually required. Other time parameters include armature changeover, contact chatter, pulse distortion etc.

5.4 Request of ambient adaptability:

   According to the application fields, in order to guarantee the relay operates reliably, ambient adaptability items mainly include temperature (max. and min temperature, temperature cycle, temperature shock, low temperature storage etc.), humidity resistance (high humidity at normal temperature, high humidity at high temperature), low air pressure resistance, vibration stability and vibration strength, shock stability and shock strength, constant acceleration.

   In special environment, it also includes salt-mist resistance, mildew resistance, radiation resistance, transportation, storage etc.

5.5 Requests of life and failure ratio:

   When relay works under the specified ambient, specified contact load, and in specified operating times, the failure times should not exceed the specified times. The failure refers to the contact freezing that makes the contact voltage drop exceed the specified level when the contacts pick up when the relay is working.

   All the relays that have the requests of established reliability index have specified class of failure ratio.

5.6 Requests of safety specification:

   To avoid electric-shock and fire, the product must accord to the safety stipulation of relevant country, e.g. CCEE of China, UL of America, CSA of Canada, VDE and TUV of Germany etc.
Not all the relays should reach all the requests. The technical requests differ from the different application conditions.