Room humidistat, 1- or 2-step

Electromechanichal room humidistat with hair element for controlling humidification and/or dehumidification in HVAC systems. The setpoint knob can be locked. Can be used to control a humidifier or a dehumidifier or for on/off controlling of a fan. Can also be used to give an alarm when the humidity exceeds or falls below a pre-set level.