EMD-4000B Datasheet, PDF (1/4 Pages) Amphenol Corporation – Excellent interchangeability

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EMD-4000B
Humidity Sensor
The EMD-4000B is a bulk resistance-type humidity
sensor based on the impedance change of a thin-
film polymer due to water vapor absorption. The
polymer is deposited on Bismuth alloy terminals,
which are set on a ceramic substrate. The sensor
is excited by a low voltage alternating current and
the impedance measured as a function of relative
humidity.
The thin-film polymer consists of chemical
functional groups that disassociate into ionic
species as water vapor is absorbed. This results
in increased electrical conductance through
the sensor or a decrease in impedance. The
impedance is an inverse exponential function of
the surrounding humidity.
Features
• Excellent interchangeability
• Standard Accuracy 5%
• Economical
• Recovers from condensation
• Good resistance to chemical vapors
• Fast response
• Low hysteresis
Amphenol
Advanced Sensors