S4000CH Combustible Gas Detector0 pages

Combustible Gas
GENERAL MONITORS
Protection for life.

MODEL S4000CH
Features

Benefits

• Compatible with Automatic
Remote Gas Calibrator

• Fully automatic calibration

• Event logging

• Stores fault, gas check, calibration,
and alarm event history

• HART and Modbus
communication

• Provides complete status and
control capability in the control
room

• 4-20 mA output

• Industry standard output for remote
alarm and fault indication

• Warning, Alarm & Fault Relays

• Provides local alarm capability

• Calibration, Calibration Check,
Setup Modes

• Simplifies operation and
maintenance

• Remaining sensor life indication

Intelligent Sensor
for Combustible Gas Detection

• Reduces downtime by providing an
estimate of remaining sensor life

Description
The Model S4000CH Intelligent Sensor is a
microprocessor-based transmitter designed for use with
General Monitorsʼ catalytic bead sensors. The unit
features one person calibration and can virtually selfcalibrate by simply activating a magnetic switch and
applying gas. It is designed to monitor combustible
gases and vapors within the lower explosive limit (LEL)
and provide status indication and alarm outputs.
All of the Model S4000CH electronics are contained
within an explosion-proof housing so that sensor
information can be processed at the sensor site. The
detector uses a 4-20 mA analog output signal that is
proportional to 0 to 100% LEL gas concentration at the
sensor. In addition, the Model S4000CH includes
warning, alarm, and fault relay contacts that can be
used to indicate an alarm or fault condition and dual
redundant Modbus or HART communication.
Configurations with relays, Modbus, and HART are
available to meet many needs.
The Model S4000CH also includes a three-digit LED
display. This local display continuously indicates gas
concentrations during normal operation or in the Gas
Check Mode, calibration prompts during Calibration
Mode, display codes during the Setup Mode, and eight
fault codes.

The Model S4000CH has four different operating modes.
First, a normal operating mode in which alarms are active
and the display and 4-20 mA readings are proportional to
the gas concentration at the sensor. Second, a gas check
mode that allows the user to apply a gas and check the
sensor response while alarm outputs are inhibited. Third,
a calibration mode in which gas is applied to the sensor to
calibrate the unit. Finally, a setup mode which allows the
user to review or change setup options such as relay
settings, calibration level, and Modbus parameters.
Selecting Setup Mode on the Model S4000CH is
accomplished by using the magnetic switch or HART or
Modbus command. Options include:
• Calibration level
• Energized/de-energized relays
• Latching/non-latching relays
• Alarm set points for relays
• Baud rate, data format, and address for each
Modbus channel