GE General Eastern Humilab

Humilab

Relative humidity generator and calibration chamber

The GE General Eastern Humilab is a NIST-traceable relative humidity generator and calibration chamber that is continuously monitored and controlled by a chilled mirror hygrometer and precision RTD. The Humilab system is water-jacketed for thermal stability and facilitates cost-effective calibrations of relative humidity sensors, probes, transmitters, recorders, and data loggers.

The Humilab relative humidity generator and calibration chamber employs the time-proportioned divided flow method to generate relative humidity values from 10% to 90% RH. Unlike other humidity chambers that use secondary %RH sensors, pressure transducers, or wet/dry bulb temperature sensors, the Humilab has a built-in primary humidity reference standard. %RH is calculated from the fundamental chilled mirror dew point and platinum RTD temperature measurements. The chilled mirror sensor and RTD are in the same environment as the devices under test. The relative humidity is controlled, regulating a fraction of a constant flow of dry air through a saturator. The dry air is produced with an internal pump and desiccant cartridge. The air streams are temperature-conditioned and mixed to maintain the desired RH level in the test chamber.

Since the volumetric mixing ratio is a time-based control, the Humilab relative humidity generator and calibration chamber is highly repeatable. The chamber is sufficiently sized for several test articles at once. The Humilab has an inlet for dry compressed air, which extends the life of the desiccant indefinitely. The water jacket may be connected to a temperature-controlled water bath/circulator to provide standardized test conditions. The test chamber has been thermally mapped to confirm temperature uniformity of better than 0.2°C.

Relative humidity generators and calibration chambers from the Humilab Series provide analog and digital outputs (RS232) to facilitate data logging and recording. The %RH set point can be selected from the front panel, or ramp and soak profiles may be uploaded to the Humilab using Prostep software. Prostep also provides data logging via the RS232 data port. Test data may be saved to a PC as ASCII data, which can be imported into standard spreadsheet programs such as Excel.

An optional temperature controlled bath/circulator is also available.

Applications of the GE General Eastern Humilab Relative Humidity Generator and Calibration Chamber

• Calibration Labs
• HVAC and BAS Transmitters
• Pharmaceutical Instruments
• % RH Data Loggers
• % RH Recorders
• Industrial Humidity Probes
• Test Humidity Sensors
• Metrological & RadioSonde Sensors