Test Menu „Test; Opera�On, Maintenance, Inspec�On And Service Of The Detector; Usage Limits - DEGA NS III LCD Instruction Manual

4. Test menu „TEST"
Protected by password 0004. By enetering a wrong password, the detector returns to measurement mode.
The password can be changed in the menu SET -> PSWD.
Menu
4-20 mA current loop
test
Digital communica�on
test
Detector restart
Return to main menu
Opera�on, maintenance, inspec�on and service of the detector

1. Usage limits

To maintain proper opera�on of the detector it is neccesery to respect the fact, that step changes of humidity, condensa�on
or rapid changes of pressure can cause incorrect indica�on of the measured value. Each sensing technology is suited for
different methods of applica�on, which is described below. All sensors are characterized by a smaller or larger cross-sensi�vity
to other gases than those which are set. Therefore before processing project documenta�on we recommend to have the air in
the deployment area of the detec�on system analyzed.
a) cataly�c sensors: Trace amount of vapors of silicon compounds and sulfur compounds cause a permanent loss of sensi�vity,
which requires recalibra�on or replacement of the sensor. Longterm crossing of the measuring range causes a decrease in
sensi�vity. In case of an atmoshpere having an oxygen content of less than 17 %, there will be an underes�maton of the
measured value. In case of an atmoshpere having an oxygen content of more than 25 %, there will be an overes�ma�on of the
measured value.
b) electrochemical sensors: Constant exposure to toxic gases or short-term
maximum range of the sensor, can damage the electrochemical sensor, which requires recalibra�on or replacement. High
temperature along with low rela�ve humidity have a nega�ve effect on the sensor's life�me. In case of an atmoshpere having
an oxygen content of less than 1 % for longer than 1 hour, there will be an underes�ma�on of the measured value.
c) infrared sensors: Vapor acids and alkalis can etch the op�cal system and distort the measurements. A check or a calibra�on
may be neccesery.
d) semiconductor sensors: Short-term exposure to gases or vapors of organic solvents, which greatly exceed the maximum
range of the sensor, may damage the sensor and a recalibra�on or replacement may be required. In case of an atmoshpere
having na oxygen content of less than 18 %, there will be an underes�ma�on of the measured value.
e) photoioniza�on sensors: the UV lamp or sensor must be replaced regularly, its clogging may cause loss of signal.
Using „ " set the output current in a 4-22 mA range. Return to Test menu
„ "
Using „ " set the concentra�on broadcasted via RS485 in measuring range
of the sensor.. Return to Test menu „
Using „ " switch between „YES" - for restart, or „NO" for returning to Test
menu. Confirm „ ".
Return to main menu
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exposure to gases, which greatly exceed the