sierra-monitor-corporatio gas sensor modules 4101 User Manual

The Sierra Monitor Model 4101 Series provides the user
with the features needed in a stand-alone, fixed-point
hazardous gas monitor system.  Utilizing catalytic bead
sensor for combustible gas and electrochemical sensor
technology for the oxygen and toxic gas sensors, the Model
4101 provides accurate monitoring of hazardous gas
conditions.  Proven sensor design matched with reliable
state-of-the-art electronics results in the ideal complete
single channel package to protect your plant and personnel.

Automatic Low Sensitivity Check
Monitoring integrity is ensured with the automatic low
sensitivity check.  After calibration, a sensor sensivity
check confirms that the sensor response to gas is sufficient
to provide reliable operation without false indication.  If the
sensor has low sensitivity, an LED lights to indicate that
sensor replacement is due.

False Alarm Avoidance
During Power-Up and Calibration, the transmitter output is
locked at 4 mA (except Oxygen sensor modules).  The
output remains locked for five minutes directly after power
is applied or after calibration gas is removed, allowing
sufficient time to fully stabilize before coming on-line.  This
avoids erroneous readings during warm-up and prevents
alarm caused by calibration gas.

Convenient Diagnostic Measurements
Critical measurements are made at convenient jacks for a
Volt Ohm Meter.  Each measurement location is clearly
marked.  All modules have a signal output adjustment.

Simple Zero and Span Adjustments
Easily accessible potentiometers enable calibration
adjustments to be made in minutes by non-technical
personnel for reduced maintenance cost.

Flexible Alarm and Logging Options
The analog gas sensor modules can be used as part of a
facility gas risk management plan.  The 4-20 mA output
signal is ideally suited to interface with a wide range of
instrumentation for alarm annunciation and recording.

The sensor module is housed in a NEMA-7 enclosure rated
for Class 1, Division 1, Groups C, D environments.  An
optional NEMA 4 Group B enclosure is available.

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