Veris Industries HS Datasheet - Manual

HU
MIDIT
Y
VERIS INDUSTRIES
800.354.8556 +1 503.598.4564 www.veris.com
Provides Easy Field Replacement
For Veris Deluxe Humidity Sensors
DESCRIPTION
The HS replaceable humidity element is designed to lower costs and reduce
downtime. It features thin-film capacitive technology for superior accuracy and
exceptional resistance to contaminants. It is compatible with all Veris deluxe
sensors, making replacement quick and easy. No need to install a new humidity
sensing device, just insert a new element into the unit and resume operation.
These humidity elements are calibrated in a high accuracy, NIST traceable,
humidity generator. Each sensor is digitally calibrated at four different relative
humidity levels over an eight-hour period. Calibration data is programmed into
the replaceable sensing element. This computer-controlled digital calibration
eliminates errors associated with manual “trimming.” A certificate of calibration is
provided with the device.
Veris’ calibration system produces known humidity values using the fundamental
principle of the “two pressure” generator developed by NIST (H-4622). The
two-pressure method involves saturating air with water vapor at a given pressure
and temperature. Saturated gas then flows through an expansion valve where it is
isothermally reduced to chamber pressure. Gas temperature is held constant during
pressure reduction, so relative humidity at chamber pressure is calculated as the
ratio of two absolute pressures.
Temperature uniformity in the chamber is maintained by circulating a temperature
controlled fluid through a shell surrounding the test space. Highly accurate pressure
measurements are made using NIST traceable piezoresistive transducers. The
resulting system accuracy is better than 0.5% RH over all ranges and temperatures.
This system is capable of continuously supplying accurate humidity values for
instrument calibration, evaluation, and verification.
Conformal Coating Accuracy NIST
= None N = NIST (1% and
2% models only)
X = None (2%,
3%, and 5%
models only)
1 = 1%*
2 = 2%
3 = 3%
5 = 5%
U.S. Patent No. 5,844,138
HS X
Replaceable Humidity Element
Example:
HS 5 X X
HS
Year
Warranty
1
Thin-film capacitive technology
provides superior accuracy and
resistance to contaminants
ORDERING INFORMATION
HS
* 1% HS sensors used in outdoor applications
are limited by the device to 2% accuracy.
HQ0001794.B 01131