Datasheet

EE381
v1.7 / Modification rights reserved
E+E Transmitter Series EE381 are specially designed for the
measurement of water content in oil. EE381 is ideal for online
monitoring of moisture in lubrication or insulation oil, which is
very important for the long-term performance and preventive
maintenance of plant and machinery.
For instance, moisture affects dramatically the insulation
characteristics of electrical transformer oil and therefore
continuous monitoring is extremely important.
Humidity measurement in oil
Similar to the humidity in the air, the water content in oil can be
indicated by the absolute value in ppm or by the relative value
a
w
:
- ppm (mass of water / mass of oil)
- a
w
(actual water content as fraction of the water
content in saturated oil)
a
w
= 0 corresponds to water-free oil, while a
w
= 1 indicates saturated oil. a
w
measurement with the EE381
transmitter is based on the outstanding long term stability and resistance to pollution of the E+E capacitive
sensor elements series HC.
The measured physical quantities are water activity a
w
and temperature T. With these quantities EE381
calculates the water content x (ppm) in mineral transformer oils. Calculation of water content (ppm) in
non-mineral oils and lubrication oils can be achieved by programming the specific parameters of the oil into
the EE381.
EE381
EE381
Compact Transmitter / Switch
for Moisture Content in Oil
Outputs
The EE381 transmitter has two freely selectable and scaleable outputs for water activity, water content or
temperature.
The EE381 switch with two relay outputs is designed for control and alarm purposes. The status for early
warning and main alarm is indicated by LED's.
Adjustment of the a
w
/T/ppm set point and hysteresis can be achieved with the optional configuration software.
Configuration Software
The optional configuration software allows flexible and easy adjustment of the analogue resp. relay outputs
to the respective requirements.
The adjustment / calibration of the transmitters can easily be performed.
monitoring of
- transformer oil
- hydraulic oil
- ship engines
Typical Applications Features
measuring range 0...1 a
w
measurement of water content in ppm
medium temperature -40...80°C
(-40...176°F)
two relay outputs for a
w
/ppm/T
EE381
Screw Connection for Mounting - 360° positionable
The construction of this screw connection enables any
position / rotation of the mounted transmitter.
So an optimal position of the display resp. the cable
outlet is guaranteed.
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