1220 & 1220-3

Models 1220 & 1223 - Multipoint Combustibles Systems


Model 1220 - Control module system emclosure (8 channel)

     Teledyne’s Model 1220 microprocessor-controlled gas detection system is specifically designed to monitor industrial locations such as refineries and chemical plants, and warn of the presence of potentially explosive gases and vapors.

     In addition, the 1220 can activate ventilation or sprinkler systems or shut down process equipment until the danger is eliminated. Developed in collaboration with plant personnel who utilize gas detection equipment, the 1220 is a blend of flexibility and simplicity with state-of-the-art electronics.


  • Dependable microprocessor based electronics
  • 1MAN calibration
  • No field mounted electronics required
  • Rugged, field proven detectors

Building Block Concept

     Virtually every application has unique requirements beginning with the number of locations to be monitored by one system. Therefore, flexibility is a key ingredient in the 1220’s design. A 1220 system is comprised of a central control station and remote detectors. A system can be as small or as large as needed because the control station incorporates a building block concept of control modules, each of which houses up to eight channel modules connected to one or two detectors mounted in the hazardous location.

     A free standing system can accommodate up to seven control modules, 56 channel modules (figure 3) and 112 field mounted detectors. The detectors can be located well over a mile from the main system. Only AC or optional DC power is needed for the system to be fully operational.

Control Module Features

  • Accepts up to eight channel modules and 16 sensor inputs
  • Provides common alarm relay outputs from all eight channels
  • Common audible alarm and bypass switch with indicator light
  • Main power on/off control and indicator light

     Information from all eight channels is fed into a central receiver. The audible alarm and common alarm relays automatically actuate when any alarm condition exists on any channel (failure, caution, or high). Control module relays can be made to operate either normally energized or normally de-energized. A common alarm bypass switch is provided to silence the internal audible alarm, and external alarm devices are not affected by the bypass switch.

Channel Module Features

  • A 30 second time delay on start up to prevent false alarms
  • Three customer-selectable calibration modes
  • Pass code protection
  • Customer selectable alarm set points and relay functions
  • Custom backlit LCD display
  • 0-10 VDC output
  • Error codes to prevent incorrect calibration
  • Sensor sensitivity gauge
  • Separate power supplies for each channel
  • Self diagnostics with fail codes and test points

Model 1223 - 3 channel

     A channel module is a stand-alone unit with its own microprocessor, power supplies, alarm relays, self diagnostics and controls. Easy to use and service, each channel module provides self diagnostics that automatically check power supplies, sensors, signal output and connections to insure key components are functioning properly.

     Failure codes are provided to quickly locate troubles spots and assist in keeping the system online at all times. The module can be easily re-configured to operate in the dual detector configuration by simply installing the S2 activation PC board. When installed, the microprocessor automatically reconfigures itself to accommodate the second detector.

     Modifications to the channel module settings are protected by an optional pass code which prevents access to the SELECT key menus. Once the SELECT key is activated the menus are displayed. Successive key strokes advance the selection, and menus are prioritized based on anticipated usage.


  • T Two sensors per channel
  • M 4-20 mADC output
  • R RS-485 output (MODBUS Protocol )
  • V 12-24 VDc operation

detectors     Detectors

     Refined over the years, Teledyne’s rugged detector design has demonstrated exceptional performance under the harshest environments. Based on the low temperature catalytic oxidation principle, the detector utilizes stainless steel support bars in the construction of the platinum sensing beads which provide exceptional stability and long life under shock and vibration conditions.

     During operation, the beads are heated by a constant current through the heating coils. Oxidation of the combustible gases at the catalytic active bead raises the beads. This temperature rise in turn causes the resistance of the coil to increase. Measurement of the change in the coil resistance produces an accurate measurement of the concentration of the combustible gas. The inert bead compensates for changes in coil resistance which might occur from other phenomena other than the combustible gas.

     A wide variety of sensor configurations are available to meet specific application requirements including stainless steel sensor housings, lead or silicone resistance, and 



  • Aerosol filling
  • Automotive manufacturing 
  • Battery charging
  • Chemical plants
  • Loading docks
  • Metal coating
  • Sewage plants
  • Paint and varnish manufacturing
  • Petroleum refineries
  • Pipelines
  • Power plants
  • Landfills
  • Semiconductor manufacturing
  • Solvent manufacturing
  • Utility companies