Humidity Controller

The Humidity Controllers regulate the temperature and relative humidity in BerILL chambers. Each system is connected to two thermostatic baths and operated by a Process Logic Controller M251 from Schneider. From the temperature and humidity setpoints provided by the user, the PLC determines the reservoir and sample temperatures (Antoine's equation). It then controls their variation using an overshoot technique (to earn time) or not. The touch screen graphical user interface displays the evolution of the physical parameters, the actual operated humidity chamber and other parameters.

As startup, the controller is in manual mode and the user must enter the sample and reservoir temperature setpoints. It is also possible to switch On/Off the heater of the goniometer and to request a goniometer temperature. In automatic mode, the user provides the temperature and relative humidity setpoints of the sample. The PLC calculates the temperature of the reservoir for the selected water (H2O or D2O). It enables automatically the heater of the goniometer whenever needed.

The PLC also provides an overshoot technique to speed up temperature and humidity changes: when enabled, the overshoot option requests the relative humidity setpoint + 10%RH until some condition is satisfied. This techniques relies on measurements performed in automatic mode at 10, 20, 30, 40, 50, 60, 70, 80, 90 and 100%RH. The PLC stores automatically optimum parameters for each plateau and reuses them for altering the overshoot option.

Humidity Chamber (1:04HCAL10, 2:05HCAL10, 4:06HCAL10)X 40244
Remote (true) / Manual (false) modeX 40246
Sample temperature setpoint (°C)XX40200
Relative humidity setpoint (%RH — Auto mode only)XX40202
Reservoir temperature setpoint (°C — Manual mode only)XX40204
Goniometer heater mode (0:OFF/1:ON — Manual mode only)XX40250
Goniometer temperature setpoint (°C — Manual mode only)XX40248
Goniometer temperature (°C)X 40252
Sample bath temperature (°C)X 40206
Reservoir bath temperature (°C)X 40208
Sample top temperature (°C)X 40210
Sample bottom temperature (°C)X 40212
Reservoir temperature (°C)X 40214
Relative humidity (measured — %RH)X 40216
Relative humidity (calculated — %RH)X 40218
04HCAL10 humidity sensor - SlopeX 40220
04HCAL10 humidity sensor - OffsetX 40222
04HCAL10 pressure sensor - SlopeX 40224
04HCAL10 pressure sensor - OffsetX 40226
05HCAL10 humidity sensor - SlopeX 40228
05HCAL10 humidity sensor - OffsetX 40230
05HCAL10 pressure sensor - SlopeX 40232
05HCAL10 pressure sensor - OffsetX 40234
06HCAL10 humidity sensor - SlopeX 40236
06HCAL10 humidity sensor - OffsetX 40238
06HCAL10 pressure sensor - SlopeX 40240
06HCAL10 pressure sensor - OffsetX 40242
Equipment status — Idle bitX 40 100.0
Equipment status — Running bitX 40 100.1
Equipment status — Local (true) / Remote (false) bitXX40 100.2
Equipment status — Fault bitX 40 100.3
NOMAD tolerance range (for Idle and Running)XX40 102