Checking measuring equipment

For optimal climate control, accurate and reliable measurement is essential. As well as maintenance to the RH measuring sensors, periodically checking the measuring equipment should also be a standard item on the maintenance chart.

Checking the sensors.
A simple and quite reliable way to check all the sensors is to run the fan at half speed when the growing rooms are empty. All other inlets including air inlets must be closed. Remove the wick from the wet bulb and ensure that all compost sensors are hanging unobstructed. After ± 1 hour it is easy to identify which sensors differ greatly (e.g. more than 1°C). The difference between the dry and wet bulbs of the RH measuring equipment must never exceed 0,2 °C !

Checking CO₂ measurement.
After calibrating the CO₂ meter using a zero setting cartridge, check the tubes and magnetic valves of the growing rooms + outside for leaks. Attach the zero cartridge (vertically) to the tube. If growing room or outside air is measured, the CO₂ meter value should show 0 ppm. Other values indicate a leak, meaning mixed air is reaching the CO₂ meter.

Jan Gielen, Specialist climate & energy, C point