TrolMaster SA-S8 Replacement CO2 Sensor | For the BETA-8 Controller

What the TrolMaster SA-S8 Replaces in a BETA-8 On a BETA-8 the controller is a box on a wall and the sensor is a head on a lead hanging near the canopy. Everything that actually measures sits in that head. The sensing element is NDIR, accurate to plus or minus fifty parts per million. It sits on a sixteen foot cable, with a photocell built into the same head. That photocell is what stops carbon dioxide injection during the dark period. So this part carries two functions rather than one, and losing it costs both the reading and the night behaviour. The head is the component that lives in the room rather than on the wall, which is why it is the part that wears. It sits in warm humid air, it collects dust, and it is the thing that gets knocked when a canopy is moved. Making it a service part is the right design, and it means a controller with a drifting reading does not become scrap. When an NDIR Head Needs Replacing Rather Than Cleaning Infrared measurement drifts slowly over years rather than failing outright, and that is what makes a bad sensor hard to spot. Watch for three particular patterns. A reading that never moves regardless of injection or ventilation is the clearest, because room levels always move. A figure that sits implausibly low while a regulator runs continuously points the same way. So does one that sits high while a room is being flushed. Cross-check with a separate meter before spending anything, since a controller arguing with itself costs less to diagnose than to replace. Dust on the head is worth clearing first, gently and dry. Where the photocell is the failing half, the symptom is different again and easy to misread as a control fault. Injection that never begins under lamps, or never stops in darkness, points at the light sensing side rather than the gas side. Key Features Function: The replacement remote sensor head for a BETA-8 controller Two jobs: It carries both the gas measurement and the photocell Accuracy: An NDIR element, accurate to plus or minus fifty parts per million Cable: A sixteen foot lead Why it wears: The head lives in warm humid air and collects dust Drift symptom: A reading that never moves whatever the room is doing Photocell symptom: Injection that never starts under lamps or never stops at night Before replacing: Cross-check against a separate meter and clear dust gently Service part: A drifting sensor does not force a whole controller replacement Technical Specifications Specification Value SKU SA-S8 Brand TrolMaster Type Replacement CO2 sensor head Compatible controller BETA-8 Digital CO2 PPM Controller Sensor technology NDIR Accuracy Plus or minus 50 PPM Cable 16 ft Photocell Built into the sensor head Packed carton 11 x 4 x 4 in and 1 lb