Spotlight: Gas sensors
A gas sensing element is the primary element in a gas-detection system that responds to the presence of a combustible gas, including any reference or compensating unit. Gas sensors interact with a gas to initiate the measurement of its concentration. It then provides output to a gas instrument to display the measurements. Ammonia, aerosols, carbon dioxide, carbon monoxide, chlorine, dust, fluorine, hydrocarbons, hydrogen, nitrogen dioxide, oxygen, and sulfur dioxide are just a few of the common gases measured by gas sensors.
The advanced IR2100 Infrared Point Gas Detector is now rated SIL 2 suitable. The IR21 00 is designed for operation for application in oil/gas production, chemical processing, wastewater treatment, and other process industries where combustible gases pose a potential explosive threat to people, equipment and facilities.
The IR2100 has the CE Marking and is certified by FM, CSA, ATEX, and GOST. It continuously monitors hydrocarbon gases and vapors within the lower explosive limit. It features a true fail-to-safe operational design for superior performance without relying on a sintered flame arrestor, which can clog and degrade performance.
The IR2100’s gas detector sensor measures the absorption of IR radiation passing through gas using a dual beam, single-detector method of operation. The IR detector measures the intensity of two specific wavelengths: one at a reference absorption wavelength and the other outside of the absorption wavelength. The combustible gas concentration is determined by comparing these two values. The gas detection sensor features heated IR optics. Its microprocessor logic allows it to discriminate between dirty optics that require cleaning and other potential faults. The detector operates with a 4-2OmA analog output that Is proportional to 0 to 1 00% LEL gas concentration.
Catalytic bead combustible gas sensor
The5100-02-ITistheonly catalytic bead combustible gas sensor with a six-month calibration cycle. Now the user can have the advantage of long term calibration of an IR sensor and cost effectiveness and the broad detection range of the proven catalytic bead sensor. This long term calibration cycle has been performance tested and approved by Factory Mutual.
The 5100-02-IT provides interface via 4-20 mA, Modbus RS-485, or proprietary Sentry bus. The 51 00-02-IT is a standalone module with the features required to provide the due diligence expected in hazardous areas including: FM approved for performance and area safety requirements including Group B, integral scrolling LED with magnet operated menu and easy, non-intrusive calibration, isolated 4-2OmA, Modbus RTU, integral alarm relays, and it is SIL2 approved.
Gas monitors
The SensAlert Plus gas monitors incorporate advanced data retrieval, time-stamped sensor activity, configurable and assignable current fault signals (between 1mA - 4mA), and virtual relay notification. These tools provide the information necessary for truly effective predictive maintenance.
SensAlert Plus maintains and displays (or transmits via HART) the following data: percent remaining sensor life, timestamped calibration record, time weighted average (TWA) exposure, missing or nonfunctional sensor, sensor test-on-demand (TOD) result, output current loop fault, head or sensor fault, and calibration error.
Within the FM approved intrinsically safe sensor head is an optional TOD gas generation cell. The TOD cell performs a bump test at programmed intervals or by manual initiation. This feature eliminates manual bump testing and provides the option of performing the test with the 4-2OmA output active or temporarily inactive.
SensAlert Plus accepts toxic, Oxygen, catalytic, and infrared intelligent sensors, all of which may be shop calibrated and hot-swapped in the facility without declassification. SensAlert Plus is FM and ATEX approved for most hazardous electrical classifications.
Signal conditioning, relay modules
A family of 6mm wide, DIN rail mount, signal conditioning and relay modules, designated the 857 Series, aka JUMPFLEX, offer a system approach to signal switching and conditioning. A common profile allows the sharing of accessories, such as jumpers. System features include; pre-marked modules for easy circuit identification, marking tag holder for module identification, built-in indication for power or signal status, and CAGE CLAMPS wiring technology for fast, easy, and maintenance-free wiring. The 857 Series signal conditioners consist of 12 different modules, both configurable and dedicated modules are available. Signal types supported include current, voltage, Hart protocol, RTDs and thermocouples. The 857 Series relay modules includes a growing line of pluggable relay types. Up to seven different modules offer a wide variety of AC/DC coil voltages and are capable of switching loads up to 25OV and 5A.
Self-cleaning mass flowmeter
The Model GF90 flowmeter maintains optimum flow measurement performance while reducing maintenance costs in rugged oil and gas refining applications. The insertion style GF90 mass flowmeter’s self-cleaning purge ports minimize maintenance requirements and costs in dirty gas applications. By connecting the GF90’s purge ports to compressed air, inert gas, or solvent purge lines, process contaminants can be removed regularly and without un-installing the flow sensor element from the pipe to ensure continuous high accuracy measurement and significantly reduce maintenance activity. The GF90 utilizes a thermal mass gas flow sensing element designed with 316 stainless steel and nickel-braze construction.