EsiWelma Srl
URS20SI_en.doc - rev. 0
Oxygen detectors – URS20SI
20/10/2010
Gas detection systems for industrial environments
1/8
Oxygen detectors
IP65 protection rating
URS20SI
11…28Vdc power supply.
Electrochemical cell sensor designed for the detection of oxygen (O
2
).
Up to three alarm thresholds plus sensing element fail.
LED on sensing element body to indicate operating status.
Automatic countdown of sensor life.
Use
The URS20SI detectors are used to detect oxygen excess or deficiency in non-
classified areas.
An
oxygen excess
forms if it leaks in hospitals, laboratories, welding centres and,
more in general, where oxygen is stored.
Oxygen deficiency
is an indirect measurement of the presence of other explosive or
asphyxiant
gases that deplete the oxygen in the air.
URS20SI sensors can be used in stand-alone mode with 4…20mA output or with an
optional voltage-free contact relay card having the following four digital outputs:
- Pre-alarm, 1
st
alarm threshold, 2
nd
alarm threshold, sensor fail.
Operation
If there is an oxygen leak or an absence of oxygen, the detector compares the
measured concentration value with the threshold limit setpoints and energises the
associated relays. Information on the measured concentration value is always at the
4…20mA output.
Ordering
To order, simply state the part number:
URS20SI
.
For special versions, on request, please contact Customer Service.
