The B12 gas detector is a flexible component system providing a variety of options to meet individual gas detection and alarm requirements.  Series B12 transmitters are loop-powered instruments that transmit a 4–20 mA signal linearly proportional to gas concentration.

The B12 detection systems consist of individual modules that can be located where required.  Sensor/transmitters, located in the area where gas leakage or buildup might occur, provide the basic measurement for the system. Sensor transmitters are available in either NEMA 4X or explosion-proof versions.

Transmitters are normally supplied with the sensor close coupled to the enclosure. However, for special applications, the unit can be supplied with separate sensors that can be located up to 25 feet from the transmitter. Sensor duct mounting adapters and sensor flowcells can also be provided for specific applications.

When remote display and alarm relay functions are required, the B12 Wet Gas Transmitters can be connected to ATI's B14 Alarm Receiver System. This system will provide direct digital display of gas concentration, plus 3 alarm setpoints, remote alarm reset input, and retransmitted 4-20 mA output. Or, the B12 transmitter may be used separately and tied directly to the users' DCS, PLC, or other equipment.

Universal power supply modules provide DC power to receivers. The power supply is housed in a compact module similar to the receiver, and will accept inputs from 85 to 265 volts, AC or DC, without adjustment. The power supply also provides a power failure relay and charging for an optional battery back-up unit.

The Gas Transmitter for the detection of ______________ (Specify Gas) shall be provided to monitor the ambient gas concentration in ___________ (Specify Location). Each gas transmitter shall consist of a NEMA 4X transmitter enclosure with a close coupled gas sensor. The Gas Sensor/Transmitter shall be ATI Series B-12 loop powered 2-wire transmitter with a 4-20 mA analog output signal proportional to the gas concentration.

The Gas Transmitter shall measure gas concentrations in atmosphere using electrochemical diffusion sensor technology and electrically connect to the transmitter PC board via plug-in connector. Calibration shall be by zero and span potentiometers located on the transmitter PC board. For proposes of calibration, test loops for voltmeter connection shall be located on the transmitter PC board.  Output shall be 4-20 mA analog loop powered, 12 to 30 VDC.

Optional

1. Each gas transmitter shall consist of a NEMA 4X transmitter enclosure with a LCD display located on the enclosure lid with a close coupled gas sensor. The Gas Sensor/Transmitter shall be ATI Series B-12 loop powered 2-wire transmitter with a 4-20 mA analog signal proportional to the gas concentration.
    
2. Each gas transmitter shall consist of a transmitter enclosure rated explosion proof for Class 1, Division 1, Groups B, C & D with a close coupled gas sensor. The Gas Sensor/Transmitter shall be ATI Series B-12 loop powered 2-wire transmitter with a 4-20 mA analog signal proportional to the gas concentration.
    
3. Each gas transmitter shall consist of a NEMA 4X transmitter enclosure with insertion sensor that can be located up to 25 feet from the transmitter. The insertion sensor shall be provided with a ¾” NPT insertion adapter specifically designed to adapt the sensor for pipe or duct mounting and enable the sensor to be extracted from the process for calibration or servicing. The insertion probe adapter shall contain a gas calibration chamber in the extracted position with a 1/8” barb fitting port for attachment of calibration gas.