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KAHN INSTRUMENTS, INC.
885 Wells Road, Wethersfield, CT 06109
Tel: 860-529-8643; Fax: 860-529-1895
E-mail: [email protected]
www.kahn.com
1.
INTRODUCTION
1.1
General
Kahn Instruments manufactures a wide range of on-line and portable instruments for the
determination of moisture content in air and gases. In addition, the company
manufactures humidity calibration systems for industrial and scientific users.
The Series 4000
Integrale
Precision Dewpoint Hygrometer is a precision instrument
which may be used in calibration and standards laboratories and in exacting process
monitoring and control applications where wide humidity range and high accuracy is a
prime requirement.
A direct indication of dewpoint to a resolution of 0.01°Celsius (°C) is provided by the
instrument display. The dewpoint may also be displayed in a number of other engineering
units including °Fahrenheit (°F), Parts Per Million by Volume (PPM(V)), Parts Per Million
by Weight in SF
6
(PPM(W) in SF
6
), grams per cubic meter (g/m
3
) and grams per kilogram
(g/kg). Additionally, the instrument can measure and display the gas temperature using a
remote PRT probe (supplied as standard). This temperature may be displayed in °C or
°F. Relative Humidity (%RH) may then be calculated from the fundamental gas dewpoint
and temperature at atmospheric pressure. The instrument may also be configured to
display measured gas pressure (KPa) using an external pressure transducer, and use
this measured pressure to calculate pressure compensated PPM(V), PPM(W) for SF
6
,
g/m
3
and g/kg.
The Series 4000 is based on the cooled mirror principle and is derived from a highly
successful Transfer Standard Dewpoint Hygrometer. This Transfer Standard was
developed during the early 1980's in collaboration with the EEC Bureau of Reference as
a European link to the National Institute of Science and Technology (NIST) humidity
standard in Washington, USA.
Dewpoints over the range -60°C to +35°C may be measured with the Series 4000
Integrale
instrument. This is equivalent in terms of absolute humidity at atmospheric
pressure to a range of 10.7 ppm(V) to 140,000 ppm(V) (parts per million by volume).
The Series 4000 Precision Dewpointmeter is also available in a “remote” configuration,
where the dewpoint sensor assembly is located in a separate enclosure, remote from the
monitor unit. Full range capability of the Series 4000 instrument can be achieved using
the remote version with external cooling / heating to achieve the extremes of temperature
required. In this configuration dewpoints over the range -95°C to +85°C may be
measured (equivalent to 0.04 ppm(V) (parts per million by volume) to almost 50% V/V
(percentage moisture by volume)).
