HH920B-IS-Series

Supported Applications

The Omega HH920B-IS Series (Models 921B and 922B) comprises Intrinsically Safe Thermocouple Meters designed for use in hazardous locations. These handheld instruments are certified for environments including Petro Chemical Plants, Fueling Stations, Aircraft Maintenance, Custody Transfer operations, Semiconductor facilities, Pharmaceutical plants, and Food Facilities.

The series supports temperature measurement using standard thermocouples (Types K, J, T, E, B, N, R, S) via Mini-TC connectors. Model 921B provides a single input channel, while Model 922B offers dual inputs for simultaneous monitoring or differential calculations.

Operating Conditions & Performance

The series delivers basic accuracy of ±(0.04% |rdg| + 0.3 °C) conforming to ITS-90 standards. Measurement ranges vary by thermocouple type, spanning from -250 to 1820 °C (-418 to 3308 °F). Specific documented ranges include:

• Type K: -200 to 1372 °C; -328 to 2502 °F; 73 to 1645 K
• Type J: -210 to 1200 °C; -346 to 2192 °F; 63 to 1473 K
• Type T: -250 to 400 °C; -418 to 752 °F; 23 to 673 K
• Type E: -250 to 1000 °C; -418 to 1832 °F; 23 to 1273 K
• Type B: 600 to 1820 °C; 1112 to 3308 °F; 873 to 2093 K
• Type N: -250 to 1300 °C; -418 to 2372 °F; 23 to 1573 K
• Types R and S: -50 to 1767 °C; -58 to 3213 °F; 223 to 2040 K

The instruments operate in ambient temperatures from -20 °C to +50 °C (-4 °F to +122 °F) and altitudes up to 4600 m (15,092 ft). Humidity tolerance is rated at 5 to 95% RH for 10 to 30 °C. The display features a four-digit LCD with auto-resolution (0.1° below 1000°, 1° above or equal to 1000°) and updates readings three times per second.

Configuration Options

The series is configured for hazardous location compliance through intrinsic safety certifications including Ex ia IIB T4 Ga, Class I Division 1 Group C and D (T4), and Zone 0 AEx ia IIB T4. Additional approvals include CE 0539, DEMKO 19 ATEX 1970 Rev. 0, and IECEx UL 19.0010.

Key configurable features and options across the series envelope include:

• Sensor Inputs: One Mini-TC connector (Model 921B) or two Mini-TC connectors (Model 922B).
• Data Functions: Data hold, backlight with 30-second timeout, and statistical calculations including Minimum, Maximum, Average, Range, Standard Deviation, and T1-T2 differential (Model 922B only).
• Power Supply: Three AA alkaline batteries (IEC LR6, ANSI 15) with a typical life of 2000 hours.
• Mechanical Protection: Rated for shock up to 30g Half Sine and vibration from Random 10 Hz to 500 Hz at 0.03 g²/Hz; tested for four drops from 1 m onto concrete.
• Accessories: Factory-installed or user-installed Tilt Stand/Magnet/Hanger (Models 921-910 and 921-912), printed operation manual, and calibration with Statement of Traceability.

Key Product Differences

The primary distinction between the two models in this series is channel count. Model 921B is a single-input Intrinsically Safe Thermocouple Thermometer weighing 300.9 g (10.6 oz) including batteries. Model 922B is a dual-input version weighing 303.2 g (10.7 oz), enabling the T1-T2 differential function and simultaneous monitoring of two thermocouples.

Both models share identical physical dimensions of 193 X 84 X 28 mm (7.6 X 3.3 X 1.1 in) and conform to MIL-PRF-28800F, Class 2 standards for ruggedness. The series includes a three-year warranty on parts and workmanship with a two-year calibration guarantee.