Humidity
Selecting points and preparing humidity instruments for calibration
Relative humidity responds to temperature, airflow, stabilization and sensor condition. Points should therefore represent actual use and risk rather than a generic plan.
Select points from risk and use
Choose low, middle and high operating values and add critical controls for storage, cleanrooms, cabinets or processes with specific requirements.
- State RH and temperature ranges
- Provide alarm and acceptance limits
- Identify channels or probes
- Agree stabilization and repeat cycles
Prepare the instrument and sensor
Check batteries, display, cables, connectors and settings. Declare chemical vapour, condensation or other history that may affect the sensor.
- Do not blow or wipe an exposed sensor without instructions
- Include the readout used with the probe
- Keep equipment away from condensation
- Record the normal installation position
FAQ
Why can humidity stabilization take longer than temperature?
The sensor and protective materials must exchange moisture with the environment until equilibrium. Time depends on sensor design, airflow and the previous condition.
Should temperature be calibrated with humidity?
When both values are reported and used together, specify both parameters because temperature affects relative humidity and interpretation of results.