Temperature: separate air conditions from product conditions
Room air, supply air and stored product temperatures answer different questions. A room sensor describes its surrounding air; a correctly installed product probe helps track the crop's thermal response. Their readings should not be treated as interchangeable.
For vegetable storage, define reference locations for the crop, return air, conditioned supply air and outdoor air where relevant to the control strategy. Use several locations when the room geometry or loading creates distinct zones.
Protect representative air sensors from direct sun, radiant heat, cold surfaces and accidental contact with produce. A supply-air probe belongs in the intended air stream; a room reference probe should not be dominated by that same jet.
RTD probes and digital transmitters are common options. Check the sensor characteristic, wiring configuration and controller input before replacing an existing device.