Technical Information
Reed Sensor
The reed switch is the major component in any reed sensor, so understanding the characteristics and capabilities of the reed switch is very important in understanding reed sensors. See the Reed Switch Technical section for further information in this regard.
There are several considerations in incorporating a reed switch into a sensor capsule, such as damage to the reed switch from mechanical shock and change in sensitivity due to mechanical stress. Depending on the type of mechanical shock, the damage can take the form of a loss of the hermetic seal, a change in sensitivity, or no operation due to glass capsule breakage. Fortunately, Hamlin has much expertise in reed sensors and produces custom as well as standard reed sensors with high levels of quality and reliability.
There are also considerations when using a reed sensor. See the Reed Switch Technical section for the many considerations that are the same as for both reed sensors and reed switches, such as electrical switching load, activation methods, etc. Since a reed sensor is a magnetic sensor, ferromagnetic materials such as steel in close proximity to the sensor can influence its behavior. Motors, transformers, and other high current electrical devices near the reed sensor may also cause unwanted influence. Another influence to be aware of is temperature. Both magnets and reed sensors become more magnetic at low temperatures and less magnetic at high temperatures. The amount of change with temperature depends on the type of magnet and reed switch used.
There are many options in Hamlin reed sensors. Sensor capsules may be plastic or stainless steel. Mounting may be with screws or by soldering to a circuit board. Sensors may be placed into a hole and held in place with nuts (threaded sensor) or with setscrews or retaining clips (firecracker sensors). Electrical termination may be for a circuit board, by an integrated connector, or wires may be terminated with connectors, terminals, fastons, or just tinned leads. Although Hamlin offers a wide variety of standard parts, they cannot fit every application. That is why Hamlin works closely with customers to provide custom solutions, including additional components such as resistors, triacs, or circuit board related work. Just contact us for assistance.
Application Note:
Soldering Temperatures
Though Hamlin parts are generally no more temperature sensitive than other common electrical components, this application note recommends maximum temperatures and times for soldering Hamlin parts.