OSAT-Series

Supported Applications

The OSAT Series are intrinsically safe, non-contact infrared temperature sensors for use in hazardous areas. Each sensor measures the temperature of an area of the surface of a solid or liquid and transmits it as a two-wire, linear 4 to 20 mA signal, making it a drop-in replacement for a conventional transmitter in explosive-atmosphere installations.

With ATEX, IECEx, JapanEx and UKCA approvals, the OSAT is certified for Zone 0, 1 and 2 (gas) and Zone 20, 21 and 22 (dust) when used with a suitable intrinsically safe barrier or isolator. An adjustable emissivity setting lets it measure a wide variety of target materials including food, paper, textiles, plastics, leather, tobacco, pharmaceuticals, chemicals, rubber, coal, asphalt and paint. Its stainless-steel body suits it to petrochemical, pharmaceutical and process plants where combustible gas or dust may be present.

Operating Conditions & Performance

The sensor provides a 4 to 20 mA two-wire output with an accuracy of ±1°C or 1%, whichever is greater, and repeatability of ±0.5°C or 0.5%. Response time (t90) is 240 ms and the spectral range is 8 to 14 µm. Emissivity is user-configurable from 0.20 to 1.00 (pre-set to 0.95) via the optional USB adapter. The minimum temperature span is 100°C and the maximum is 1000°C.

Supply voltage is 12 to 24 Vdc ±5% with a maximum current draw of 25 mA. The Stainless Steel 316 housing measures Ø 20 mm x 150 mm in length and mounts on an M20 x 1.5 mm thread, length 46 mm, supplied with two mounting nuts. The sensor is rated IP65 (NEMA 4), operates over an ambient range of 0°C to 70°C at up to 95% non-condensing humidity, and tolerates an ambient pressure of 80 kPa (0.8 bar) to 110 kPa (1.1 bar). It is CE marked, RoHS compliant and ISO 9001 certified.

For hazardous-area use the OSAT carries the IECEx gas classification Ex ia IIC T4 Ga and dust classification Ex ia IIIC T135°C IP65 Da, with intrinsic-safety entity parameters of Ui = 28 V and Ii = 93 mA. Supply voltage must be provided by a suitably rated safety barrier or isolator, and because the dust certification relies on the enclosure, the device must not be opened.

Configuration Options

Every OSAT shares the same intrinsically safe design and 4 to 20 mA output; variants differ along three axes selected in the part number:

• Field of view — 2:1 (211), 15:1 (151) and 30:1 (301) divergent optics, plus a close-focus option (801) giving a 5 mm diameter spot at 100 mm.
• Temperature range — LT (-20°C to 100°C), MT (0°C to 250°C), HT (0°C to 500°C), XT (0°C to 1000°C) and an ST custom range.
• Cable length — factory-fitted 5 m, 10 m or 25 m leads (codes 05, 10 and 25).

A tighter field of view reads smaller or more distant targets, while the temperature-range code sets the span the 4 to 20 mA output is scaled across. The "C" designation indicates the sensor is user-configurable via the optional OSAT-210-USB adapter, and an air-purge collar and mounting brackets are available as accessories.

Key Product Differences

Models follow the scheme OSAT-<field of view>-<temperature range>-C-<cable length>, for example OSAT-151-LT-C-05. Representative variants include:

• OSAT-151-LT-C-05, OSAT-151-MT-C-10, OSAT-151-HT-C-25 and OSAT-151-XT-C-10 — 15:1 optics across the range codes.
• OSAT-211-MT-C-05 and OSAT-211-XT-C-10 — 2:1 wide-angle optics.
• OSAT-301-LT-C-10, OSAT-301-MT-C-05 and OSAT-301-XT-C-25 — 30:1 optics.
• OSAT-801-LT-C-25 and OSAT-801-MT-C-05 — close-focus optics.

Accessories include the OSAT-210-USB adapter and configuration software, the OSAT-210-APM air purge collar, and OSUSB-FBL fixed and OSUSB-ABL adjustable mounting brackets, so a sensor can be specified precisely for the target, distance, wiring run and mounting the hazardous-area installation requires.