T wo types of gas sensor modules are available for
the Sentry Gas Risk Management System. For
the more common gases such as Combustible
Gas, Oxygen, Carbon Monoxide, Hydrogen Sulfide, Chlorine and Ammonia, Sierra Monitor offers
the IT Series Smart Gas Sensor Modules. More
information on the IT Series is available in the specific IT Series data sheets. For other gases Sierra
Monitor offers the 5100 Series Gas Sensor Modules described in this data sheet.
Sierra Monitor toxic gas sensor modules utilize electrochemical technology to achieve the most accurate and reliable monitoring of gas concentration.
All Sentry 5100 Series sensor modules easily interface to the Sentry controller. Each module has
a unique address, which allows signals from multiple modules to be multiplexed for communication
with the controller on the same cable. All Sierra
Monitor gas sensor modules are designed for hostile or hazardous environments and are in enclosures approved for Div. 1, Class 1, Groups C, D
locations.
Sentry
Gas Sensor Modules
SENTRY FEA TURES INCLUDE:
Digital Signal Transmission Serial communication to
the controller enables multiplexing sensor modules on a
signal cable, significantly reducing installation costs. This
assures RFI and EMI immunity over extended distances.
One-Person, Non-intrusive Calibration In the calibration mode, sensors continue to monitor for hazardous
conditions until calibration gas is applied. All adjustment s
are made automatically after calibration gas has been removed. Sentry notifies the operator of calibration completion and allows acceptance or rejection of the calibration
at the controller keypad. There are no manual adjustments required at the sensor module.
Sierra Monitor Corp. 1991 T arob Ct., Milpitas, CA 95035, USA, 408-262-6611, 800-727-4377, F AX: 408-262-9042
Web Site: http://www.sierramonitor.com E-Mail: sales@sierramonitor.com
Low Sensitivity Check Automatic, post-calibration
check of sensor for proper output. Low sensitivity alphanumeric message warns of need for sensor maintenance.
Power Up & Calibration Delays At st art-up or calibration the output of the sensor is locked out and remains
locked for five minutes to avoid erroneous readings during
the warm-up period and after calibration.
Diagnostic Information The alphanumeric display on
the Sentry Controller provides easy to understand diagnostic messages.
© 2009 by Sierra Monitor Corporation
Sentry
Gas Sensor Modules
Electrochemical
Electrochemical sensors are fuel cell-like devices consisting of an anode, cathode, and electrolyte. The components of the cell are selected so a subject gas
allowed to diffuse into the
cell will cause a chemical
reaction and generate a
current. The cells are diffusion limited, so the rate
at which the gas enters
the cell is solely dependent on the gas concentration. The current generated is
proportional to the rate of consumption of gas in the cell.
Unlike other electrochemical sensors where gas diffuses
through membranes into the cell, Sierra Monitor sensors
allow gas to diffuse into the sensor through a simple capillary. The result is an extremely stable sensor with very
low temperature and pressure coefficients.
Common Specifications for All 5100 Series Sensors
Zero Drift: Less than 5% per year
Calibration Frequency: 90 Days Recommended
Transmission: Digital – RFI, EMI immune
Warranty: 2 years
Housing: Explosion proof (NEMA 7)
(Div. 1, Class 1, Groups C,D)
Optional upgrade to Group B,
NEMA 4X
Dimension: 7.6 X 4.6 X 4.2 inches
(19.3 X 11.7 X 10.7 cm)
Note that 5100-26 is larger
Weight: 2.7 lb. (1.3 Kg)
SENSORS
GAS SENSOR SPECIFICA TIONS
Gas Model Sensor Range Time Sensor Operating Relative
Number Type Response Life Temperature Humidity
Hydrogen 5100-07 Electrochem 0-1,000 PPM 90% <30 sec. 2 yr. 4
Sulfur Dioxide 5100-10 Electrochem 0-100 PPM 90% <20 sec. 2 yr. 4
Nitrogen Dioxide 5100-12 Electrochem 0-20 PPM 90% <35 sec. 2 yr. 4
Carbon Monoxide 5100-13 Electrochem 0-1,000 PPM 90% <25 sec. 3 yr. 4
Carbon Monoxide 5100-16 Electrochem 0-2,000 PPM 90% <35 sec. 2 yr. 4
(Hydrogen Tolerant to
2,000 PPM H2)
Nitric Oxide 5100-19 Electrochem 0-20 PPM 90% <15 sec. 3 yr. 4
Hydrogen Chloride 5100-21 Electrochem 0-20 PPM 90% <100 sec. 2 yr. 4
Hydrogen Cyanide 5100-22 Electrochem 0-20 PPM 90% <70 sec. 2 yr. 4
Hydrogen Fluoride 5100-26 Electrochem10-10 PPM 90% <30 sec. 1 yr. 14 o to 113
Ethylene Oxide 5100-27 Electrochem 0-20 PPM 90% <90 sec. 2 yr. 4
Note 1: Diffusion via membrane
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
to 122 o F (-20 o to 50 o C) 15-99% RH
o
F(-10
o
to 45
o
C) 20-95% RH
Sierra Monitor Corp. 1991 T arob Ct., Milpitas, CA 95035, USA, 408-262-6611, 800-727-4377, F AX: 408-262-9042
Web Site: http://www.sierramonitor.com E-Mail: sales@sierramonitor.com
© 2009 by Sierra Monitor Corporation