
High Accuracy Portable 
Relative Humidity/Temperature 
Calibrator
RHCL-2
Standard
U RHCL-2 Field Proven 
Optical Chilled Mirror 
(OCM) Technology
U Completely Self-
Sufficient and Portable 
Humidity Calibration 
System
U Highest Accuracy 
Available for Both RH 
and Temperature (AT): 
RH Range: 5 to 95% 
U 10 to 50°C Air 
Temperature Range 
U Temperature and RH 
Controlled Independently
U Automatic Correction for 
Mirror Contaminants
U Certified Measurements 
Against NIST Traceable 
Standards
The OMEGA® RHCL-2 is 
a microprocessor based, 
programmable humidity calibration 
system that is at home in the 
metrology lab or out in the field 
performing on site NIST traceable 
humidity calibrations. The RHCL-2 
is entirely self-sufficient and does 
not need compressed air or a water 
connection to operate, which allows 
this system to be truly portable. 
The system offers the highest 
accuracy available for both relative 
humidity and ambient temperature. 
Temperature and relative humidity 
are controlled independently; 
therefore, you are not limited to 
performing calibrations at the 
surrounding ambient temperature.
The RHCL-2 uses an Optical Chilled 
Mirror (OCM) primary measurement 
technique for traceability and 
feedback control. Contributing to 
ease of use are features such as 
maintenance reducing Automatic 
Balance Cycle (ABC), an integral 
ambient temperature probe, and 
D2 chilled mirror sensor which are 
located in the sample chamber 
providing not only superior accuracy 
but the fastest response.
The RHCL-2 employs a unique 
control scheme for maintaining 
precise RH control. The system 
incorporates volumetric proportional 
control valves. By independently 
modulating the “dry” and “wet” 
valves from full-open to full-close, 
and all points between, any desired 
humidity can be quickly generated. 
Additionally, because the RHCL-2 
is continuously monitoring the 
sample chamber conditions via its 
integral chilled mirror, it is able to 
instantaneously react to changes 
in humidity and maintain control 
stability.
 To Order Visit omega.com/rhcl-2 for Pricing and Details
 Model No.  Description 
 RHCL-2  Portable RH/temp calibrator
 RHCL-2-SR  Seals for sample chamber, qty 20 
 RHCL-2-CCB  Chamber covers without holes, qty 3 
 RHCL-2-DR5  Dessicant 5 lb jar
Comes complete with operator’s manual, power cord, cleaning kit and NIST certificate. 
Ordering Example: RHCL-2, portable calibrator, RHCL-2-SR, seals, and RHCL-2-DR5, 
5 lb jar of dessicant.
RHCL-2
Hu-50
Inset shows 
detail of display.
Specifications
Range: 
 RH: 5 to 95% RH @ 10 to 50°C 
 Dew/Frost Point: -40 to 60°C  
 (-40 to 140°F)
Accuracy:  
 RH: ±0.5% RH @ ±0.2°C  
 Dew/Frost Point: ±0.2°C nominal 
Slew Rate: 1.0°C (1.8°F)/sec max, 
above 0°C
Repeatability: ±0.5% 
Outputs: Anaolog (0 to 5 Vdc or 
4 to 20 mA) and RS232C 
Power Requirements: 100 to 240 Vac, 
50 to 60 Hz, 150 W maximum
Sample Flow Rate: 1 liter/min (2.0 SCFH) 
Operating Temperature (Control 
Unit): 0 to 50°C (32 to 122°F) 
Weight: 15.4 kg (34 lb) 
Dimensions: 52 W x 43.7 D x 21.7 cm H 
(20 
Enclosure: Ultra high-impact copolymer 
carrying case
5
⁄8 x 173⁄16 x 89⁄16")
H
u