Write the crop species, strain and stage before selecting a climate programme. Then distinguish room air, supply air, return air, compost or bag temperature, and product temperature. They are different measurement locations. A controller can hold its sensor at the selected value while the rear of the crop remains warmer or a nearby bed receives a drying draught.
Prepare a simple room map with marked front, middle and rear positions and representative upper and lower crop levels. Keep probes away from accidental direct spray and position them according to the instrument's instructions. Compare portable and fixed instruments using a suitable check method; two disagreeing sensors create uncertainty that should be resolved before making a large adjustment.