GasSens is a flexible component system providing a variety of options to meet individual gas detection and alarm requirements. From chemical and petrochemical plants to food processors, the GasSens system can be applied to the simplest or most complex gas detection application. Economical and low maintenance, this system is your best choice for reliable leak detection.

GasSens 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 and can be supplied with ATI’s exclusive Auto-Test automatic sensor testing system, greatly reducing operator testing requirements.

Receiver modules provide the electronic brains for the detection and alarm system. Each compact module includes a digital display of gas concentration, isolated analog output, and 4 relay outputs. Receivers may be located up to 1000 feet from sensor/transmitters for remote indication, or can provide local control functions such as valve shutoff while transmitting a 4-20 mA signal to remote displays or data loggers.

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.

ATIs A21 is a gas sample pumping system designed to draw samples from ducts or hard to access locations and deliver the samples to gas sensors located in a more convenient area. A21 Sampling Systems use a high quality diaphragm pump operated by a brushless DC motor to provide continuous sampling over long periods of time.

Sampling pumps are rated for over 10,000 hours of continuous operation and diaphragms in the pump may be changed easily if necessary. The pump will draw samples against a vacuum of up to 10”Hg. for sampling negative pressure duct systems when necessary.

In addition to the sampling pump, A21 systems contain various components needed to insure reliable sample measurement. A flowmeter mounted on the front panel allows the user to adjust the sample flowrate to the desired value, normally around 500 cc./min. Internal to the system is a loss of flow detector that will warn of sampling system problems that could compromise the gas measurement system. A loss of flow alarm light on the front panel provides local flow loss indication while an internal relay can be used to indicate this alarm remotely.

ATIs B12 2-Wire Modular 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.

Increasingly stringent air quality requirements have led to expanded use of wet scrubber systems to control air emissions. Chlorine storage facilities and chemical process plants are frequently required to scrub exhaust gas streams to remove halogen and acid gases. Unfortunately, monitoring reactive gas concentrations in moisture saturated air streams presents problems for standard diffusion sensors. Condensing water in these air lines can quickly blind diffusion sensors, rendering them inoperable.

ATI’s Series B12 Wet Gas System was developed to meet the need for reliable measurements in wet scrubber outlets for other gas streams that might be saturated with water vapor. Systems have been developed for monitoring strong oxidants (chlorine, bromine, chlorine dioxide, or ozone), acid gases (HCl or HF), and hydrogen.

The basic B12 Wet Gas System consists of a loop-powered 2-wire transmitter and a corrosion resistant sensor specifically engineered to operate at 100% RH. Sensors are designed for direct insertion into vent stacks, or may be used in a flowcell if sample can be pumped to the sensor. 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. Either way, the B12 is an excellent solution to a difficult monitoring problem.

ATI’s Series B14 Gas Alarm Module Receivers are compact electronic modules that provide local alarm, display, and signal retransmission functions for gas detection systems.

The modules are designed to accept input from either two, three, or four wire 4-20 mA transmitters located up to 10,000 feet from the receiver. They’re ideally suited for use with ATI’s Series A12 or B12 two-wire toxic gas transmitters, or Model A12-17 or B12-17 three-wire combustible gas transmitter.

B14 Alarm Receivers are DIN rail mounted modules that can be supplied in single or multiple unit enclosures. Gas concentrations are indicated directly in PPM, PPB, percent, or percent LEL with the display range selectable by the user.

Each module provides separate caution, warning, and alarm setpoints with LED bar indicators of each alarm point. LED indicators flash on initial alarm condition and change to steady on when the alarm is indicated. Modules contain individual alarm relays for each alarm setpoint. However, each relay can be assigned to any setpoint to allow multiple alarm functions at a single alarm point. Relays are configurable for either standard or fail-safe operation and for either latching or non-latching operation. A fourth LED alarm bar and relay are provided to indicate trouble conditions. The trouble alarm and relay will activate on loss of input signal or if the 4-20 mA input drops below a specific value.

Many gas detection applications require multiple sensing locations to provide adequate area protection for plant personnel. Signals from a variety of field measurement sites are often transmitted to a central location where display and alarming functions are needed. ATI’s Series C14 ScanAlarm Receiver provides a versatile central monitor that can be configured to meet most multipoint gas detection application

The C14 ScanAlarm monitors up to 16 analog 4-20 mA inputs from remote transmitters, and provides 24 VDC power for up to 16 loop-powered toxic gas transmitters or 12 3-wire combustible gas transmitters.

The two line alphanumeric LCD provides sequential display of each channel and the alarm status for that channel. Display locks on any channel that goes into alarm.

Two programmable alarm set points are available for each analog input plus a trouble alarm for each channel. Six assignable SPDT alarm relays in standard configuration, with expansion for up to 36 total relay outputs. One output relay is factory set for global alarm and one is set for system failure.

Standard RS-232/485 serial interface allows all configurations to be set up by computer and alarm events to be automatically monitored by computer. Up to 32 separate monitors can be connected to a single RS-485 communication link.

ATIs Series C16 PortaSens II Portable Gas Leak Detector is a versatile tool for performing regular leak checks in gas storage areas, around process equipment and piping, or in confined spaces prior to entry. Designed for easy one-hand operation, the detector contains an internal sample pump and a flexible sampling wand to allow pinpoint location of the source of leakage. A large character display insures that measured values are easily visible, and a back-light for the display insures readability in low or no light conditions.

A unique feature of the C16 detector is its ability to measure a variety of different gases by simply inserting the appropriate sensor for that gas. This means that one detector can be used to measure over 30 different gases or vapors, reducing the need to purchase individual detectors for each type of gas. And sensors can be changed quickly and easily, without the need for calibration when a sensor change is made. Sensors used in the PortaSens II are ATI’s newest miniaturized smart sensor modules. Each sensor module is actually a sensor, amplifier, and memory module in one compact package. Because of this design, sensor modules can be calibrated independently and simply plugged into any detector for immediate use. When installed in a detector, calibration data is loaded into the microprocessor so that no adjustments are needed. The result is that a detector can, for example, go from phosgene measurement to ammonia measurement in less than one minute.

The C16 PortaSens II is equipped with an RS-232 output which allows stored data to be downloaded to a PC through an interface cable that is supplied with the unit. A software package is included with the unit to facilitate data transfer.

ATIs D12 Toxic Gas Transmitter will accept up to 46 different sensors, greatly reducing the need for multiple transmitter models. The self-aligning sensor holder simply plugs in, with automatic sensor recognition and verification when contact is made.

For many toxic and combustible gases, ATI offers a unique sensor response testing system unmatched by any competitive transmitter. Even outdoors in high wind conditions, the Auto-Test system provides reliable response checks to insure system integrity. Sensor response is verified with an actual gas sample, generated on demand. Generators store run time information accessible to operators, and are automatically tested for compatibility with the installed sensor.

D12 transmitters provide useful features that simplify installation, operation, and maintenance. From clear menu-driven setup pages to large numerical display of gas values, you simply can’t find a more versatile transmitter. Gas concentrations are displayed in large, easy to read numbers. The display also provides alarm indication and complete menus for setting up operating parameters. Backlighting is available when operating in 3-wire mode.

Operating functions such as calibration, alarm setup, alarm reset, data view, and setup options are all available using a magnetic tool. It is not necessary to open the enclosure when making adjustments.

Transmitters are designed for operation in hazardous areas. The cast aluminum housing for the D12 transmitter is rated for Class 1, Division 1, Group B, C, D locations and is UL, FM, and CSA certified.

The transmitter is available with either HART™ or MODBUS™ protocol. The HART™ protocol supports the HART™ Universal and Common Practice Commands at 1200 baud using the Bell 202 FSK modem standard. The MODBUS™ protocol supports 9600 baud access to concentration and status information, and supports alarm setup and many other functions on either RS485 or RS232 (software selectable).

Odor control in wastewater treatment plants and sewage collection systems often requires the use of scrubber systems. Many of these scrubbers employ a wet process using hypochlorite solution to remove H2S from air streams prior to discharge. Monitoring the hydrogen sulfide in both inlet and discharge air has presented problems for standard sulfide gas sensors. ATI has developed sensor technology that now allows continuous monitoring in this type of application, where condensing humidity conditions are normal.

Designated Model Q45S, the odor monitoring system uses our standard Q45 electronics package in conjunction with a special “Wet H2S” sensor. Measurements may be made either at the inlet to scrubber systems where concentrations can run as high as 200 PPM, or at the outlet where concentrations are ideally down below 0.5 PPM. Special sensor configurations are available for either duct insertion or flowcell use.

Because Q45S systems are often monitoring gas streams with condensing levels of water vapor, provision has been made for eliminating water droplets from the sensor that could present a barrier to the diffusion of H2S into the sensor. An optional air-purge system controlled by the transmitter will periodically deliver a blast of air across the crititcal sensor surfaces to remove water droplets. This system insures a clear gas diffusion path to the sensor and reliable measurements on a continuous basis.

Q45S transmitters provide a large, easy to read LCD display of H2S concentration with a second display line to indicate other status information. An alarm contact is available for external alarming functions, and a second contact may be used for alarm purposes if the air purge system is not implemented in a given application. An isolated 4-20 mA output is provided for remote data transmission, and output spans are user programmable for ranges of 0-2.000 PPM up to 0-200.0 PPM.

A special battery-powered version of the Q45S is available for use in temporary installations. This system runs on an internal 9 volt battery and contains a data-logger for collecting information on existing air collection systems. A standard 9 volt battery will operate the unit for 4 days, while a 9 volt lithium battery will provide about 10 days of operation. Data is easily downloaded to a standard PC using software supplied with the unit.