Combustible Gas Alarm Systems

Maintaining a high degree of safety when monitoring potential accumulation of explosive gases is both affordable and very easy to implement. While it is a relatively rare occurrence, it can be a life-threatening hazard. With a simple low cost approach, it need not be of concern. Let us customize a compact, affordable and effective solution that could be the difference between a routine day and one with serious consequences.

Gas alarm systems are ideal for applications that require simple audible or visual alarms when the gas concentration exceeds the pre-set limit. For alarm annunciation, each gas monitor contains a buzzer and a relay output that can activate an external alarm or another device such as an exhaust fan.

The Model 20X/200X Series are single alarm monitors for Combustible Gas, Hydrogen Sulfide or Carbon Monoxide in the PPM ranges. An alarm signal is activated when the concentration of gas exceeds the factory-set (and user adjustable) level. Both series include the choice of alarm signals, either a digital TTL signal to interface to a Sierra Monitor Alarm Panel or a relay contact.

The Model 20X Series is in an explosion proof enclosure suitable for Class 1, Division I, Groups C and D areas. The monitor can be installed up to 500 feet from the 9V power source. The Model 200X series is in a general-purpose aluminum enclosure. This monitor has two LEDs on the face of the unit, a red LED that is actuated during alarm and a green LED indicating that the unit is operating. The standard 200X includes both a buzzer and relay contact for alarm annunciation. The monitor is also easily configured to interface with the Model 2102 Alarm Panel.

The Model 2050 Ammonia and Model 2060 Refrigerant/Halocarbon Gas Monitors are continuous duty, low cost stationary monitors for detection of high levels of ammonia and halocarbon refrigerant gases. These monitors are primarily used in and around freezers, refrigerators, and compressor rooms to warn of leaks and dangerous levels of these gases.

An alarm is activated when the concentration of gas exceeds the factory preset (and user adjustable) limit. During an alarm condition the red LED on the front of the monitor is turned on and an alarm signal is generated. The standard output signal is a digital TTL signal that can interface with the Gas Alarm Panels. A relay contact closure is available.

Semiconductor-Type Sensor

How they work - Semiconductor Sensors

Semiconductor sensors have a resistance in air that is affected by oxygen adsorbed on the surface of the sensor. Oxygen atoms capture electrons on the semiconductor surface, thereby increasing its resistance. The sensors can be impregnated with dopants such that the resistance changes when specific gases displace the adsorbed oxygen.

A solid-state semiconductor-type sensor and associated electronic circuitry ensure trouble-free, long-term operation. There are no pumps, filters or chemical cells to replace or maintain. Except periodic calibration to verify the alarm setting, no attention is required after installation. The user may adjust the alarm level by using a different calibration gas concentration. A sensor self-check feature will flash the LEDs on and off alternatively and sound an interrupted tone as a warning, should the sensor fail (open circuit). A remote alarm, the Model 2102 Dual Channel Alarm Panel can be connected up to 500 feet away.

Model 200X Series

The Model 200X Series are compact, solid-state, fixed-installation single alarm monitors designed for continuous area monitoring of Combustible Gas, Hydrogen Sulfide, or Carbon Monoxide.

The Model 200X Series consists of three separate gas monitors, Model 2001 for Combustibles Model 2003 Hydrogen Sulfide and Model 2006 for Carbon Monoxide. All of these can be mounted in any orientation. For a single-monitor installation and a local alarm, the accompanying power supply may be plugged into a standard AC source. The monitors accepts 9 - 17 VDC, CPS provides various options to accommodate most any application of these products. Our typical applications are for 24VDC or 48VDC environments.

  • Reliable operation
  • Fail-safe configuration
  • Maintenance free operation
  • Quick easy installation and connection to alarm panel
  • Self-check feature signals sensor failure
  • Optional normally operating closed relay
  • No chemical cells to replace, no maintenance other than routine calibration
  • All the electronic circuitry needed to operate the monitor contained compact unit.

The Model 2001 can detect a wide range of combustibles. Applications include combustible gas monitoring near waste dumps, holding tanks, parking garages, vehicle maintenance facilities, laboratories and chemical plants.

The Model 2003 can be used in wastewater treatment plants, laboratories and chemical plants.

The Model 2006 Carbon Monoxide Gas Sensor Module can be used to provide an early warning of CO accumulation in tanks, laboratories, chemical plants, parking garages or vehicle test facilities.


Combustible Gas 2001-00 / Hydrogen Sulfide 2003-00 / Carbon Monoxide 2006-00

Model 2102 / Alarm Panel

The Gas Alarm Panels provide a simple, easy-to-install, low-cost remote annunciator system for the 20X/200X and 2050/2060 Series gas monitors. The 2102 Alarm Panel supply DC power for the gas monitors and individual relays for activation of remote devices such as alarms, lights and fans. The Model 20X and 200X Monitors are easily configured to interface to the Model 2102 Alarm Panel

Each alarm panel has red and green LEDs for each channel. The red LED indicates an alarm condition and the green LED indicates a SAFE operating condition. Each alarm panel is easy and quick to install. The panels can be mounted up to 500 feet from the monitors.
The Model 2102 Dual Channel Alarm Panel provides LEDs for visual alarm indication and relays for each channel. An audible alarm version is available as the Model 2102-01.