TrolMaster SA-D1 Humidity Probe | Spare Sensor for the Beta-6

When a Beta-6 Needs a Replacement Humidity Sensor

A humidity controller is only as good as the probe hanging off it, and probes age faster than the box they plug into. Grow room air is the hard case, because a sensor sitting in condensing humidity for years will read low and keep reading low. The usual symptom is a dehumidifier that runs longer than it used to for the same room feel. Swapping the probe is the low cost test to run before anyone suspects the controller. The Beta-6 itself is a legacy unit in the TrolMaster range, so a spare probe keeps a working controller in service. The controller uses a precision sensor in a 16 ft remote probe, switching connected equipment through an outlet. Its ratings are 120 volts in, a relay output, a 10 A fuse at 250 volts and a 1.8 m power cord. This spare now carries the part number SA-H1 rather than SA-D1, which is worth knowing when cross referencing an older unit.

What the Beta-6 Does With It, Day and Night

The controller holds two humidity targets and a built in photocell decides which one applies. Day and night set points run from 20 to 90 percent relative humidity, with a five point deadband between switching on and off. That deadband is what stops a humidifier short cycling around a single number. A photocell means the changeover follows room light rather than a clock, so it tracks a lighting schedule automatically. It drives either a humidifier or a dehumidifier, not both at once. The probe feeds all of that, which is why a drifted sensor shows up as a room that never settles. Hang the probe at canopy height and clear of direct airflow from the unit it controls. A probe in the dehumidifier's own discharge reads the machine rather than the room. Keep the lead out of standing water even though the unit is rated for a normal room. The controller weighs about 0.56 kg and measures 275 mm by 87 mm, for anyone planning a wall position.

Key Features

• What this is: The spare humidity probe alone, not a controller
• For: The TrolMaster Beta-6 day and night humidity controller
• Part code: SA-H1, superseding SA-D1
• Probe lead: The Beta-6 probe is a 16 ft remote lead
• Why replace: An aged probe reads low and overruns equipment
• Controller set points: 20 to 90 percent, separate day and night values
• Deadband: Five points, which prevents short cycling
• Day or night sensing: A built in photocell, not a clock
• Controller electrical: 120 volts in, relay output, 10 A fuse at 250 volts

Technical Specifications