Siemens QFM81.21 : Duct Hygrostat with Covered Setpoint Dial, SPDT
Hygrostats are used for controlling and monitoring relative humidity in facilities under HVAC control. They ensure duct humidity control within the selectable range of 15 to 95% relative humidity. The hygrostats do this by controlling humidification or dehumidification equipment. Duct hygrostats can be used as minimum or maximum limiters in the supply air duct.
| Degree of protection | IP55 |
| Digital outputs | CO: 1 , Potential-free |
| Setpoint setting range | 15…95 % r.h. |
| Switching differential | 4 % r.h. |
| Operating voltage | Contact Rating: 3A@ 24 Vac/Vdc Max; 100mA Min |
| Immersion length | 130…156 mm |
| Dimensions (W x H x D) | 73 x 140 x 64 (246) mm |
| Digital output, switching current | 5 (3)A |
| Digital output, switching voltage | 250 V |
