General Eastern Humilab Data sheet

GE

Sensing

Portable and Precise

Humilab™

General Eastern Relative
Humidity Generator and
Calibration Chamber

Humilab is a General Eastern
product. General Eastern has joined
other GE high-technology sensing
businesses under a new name_GE
Industrial, Sensing.

• Primary standard: Integrated chilled mirror and
platinum RTD constantly measure test conditions

• Precise: ±0.2% RH stability

• Accurate: ±1% RH from 10% to 70% RH and ±1.5% RH
from 70% to 90% RH

• Versatile: 10% to 90% RH and 20°C to 30°C

• Self-contained operation: Equipped with desiccant and
water reservoir

• Connects to temperature bath/circulator to
standardize test conditions

• Connects to dry compressed air to extend desiccant
life indefinitely

• Records and documents: 0 to 5 VDC, 4 to 20 mA
analog outputs and RS-232 digital data stream

• Fast response: 10 minutes for 63% step change and
30 minutes to full stability

• Quality design: Stainless steel chamber

• Instant-on fittings for external dry air, circulation of
temperature controlled water and reservoir drain

• Cost effective: Ability to calibrate several %RH
instruments at once

• Ease of operation: Set to value you need by the front
panel or via PROSTEP software for ramp and soak
profiles

• Bright, easy to read control panel

• Equipped with transportation case

g

GE

Sensing

Document and Standardize

• Calibration labs

• HVAC and BAS transmitters

• Pharmaceutical instruments

• %RH data loggers

• %RH recorders

• Industrial humidity probes

• Test humidity sensors

• Metrological and radiosonde sensors

The Humilab 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.

Repeatable and Economical

The 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 system is water jacketed for
thermal stability and facilitates cost-effective
calibrations of relative humidity sensors, probes,
transmitters, recorders and data loggers.

Since the volumetric mixing ratio is a time-based control,
the system 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

Primary NIST-Traceable Calibration

The system is supplied with a certificate of calibration
and functional test data.

Prostep software enables “ramp and soak” humidity and temperature
prof iles to be loaded into the Humilab. Prostep also features data
logging. The chamber conditions are recorded as time-based ASCII data,
which can be opened in spreadsheet programs such as Excel.

conditions. The test chamber has been thermally
mapped to confirm temperature uniformity of better
than 0.2°C. Humilab provides 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.

The graph above was produced with data from the Humilab. The
calibration system provides stability of better than ±0.2% RH.

51.0

50.9

50.8

50.7

50.6

50.5

50.4

50.3

50.2

50.1

50.0

49.9

49.8

49.7

49.6

49.5

49.4

49.3

49.2

49.0

18:49

18:51

18:52

18:54

18:56

18:57

18:59

19:01

19:03

19:04

19:06

19:08

19:09

19:11

19:13

19:14

19:16

19:18

19:19

19:21

19:23

19:24

19:26

19:28

19:29

19:31

19:33

19:35

19:36

19:38

19:40

19:41

19:43

19:45

19:46

19:48

19:50

19:51

19:53

19:55

19:57

19:58

20:00

20:02

20:03

20:05

20:07