OM-70-Series

Supported Applications

The Omega OM-70 Series comprises portable data loggers with display, part of the NOMAD® Family. These compact devices are designed for logging temperature, relative humidity, and thermocouple data in applications such as coolers, freezers, greenhouses, museums, laboratories, shipping containers, warehouses, environmental monitoring, and food storage.

Operating Conditions & Performance

The series supports multiple measurement types with model-specific ranges. The OM-71 and OM-73 measure ambient temperature from -20 to 70°C (-4 to 160°F). The OM-72 measures external sensor temperatures from -40 to 70°C (-40 to 160°F), while the OM-74 operates between -18 to 55°C (0 to 131°F) and displays temperatures up to 199.9°C or °F.

Accuracy varies by model and sensor type:

• OM-71, OM-72, OM-73 Temperature: ±0.5°C (±1°F) from -17 to 50°C (1 to 122°F).
• OM-73 Humidity: ±2% RH from 10 to 90% RH @ 25°C (77°F), with a measurement range of 0 to 99% RH non-condensing.
• OM-74 Thermocouple Accuracy: Ranges from ±0.4°C (0.8°F) for E-type to ±3.3°C (6.0°F) for B-type, depending on the thermocouple grade used.

The OM-71, OM-72, and OM-73 feature a resolution of 0.1°C (0.05°F), while the OM-74 offers 0.1°C (0.2°F) for display temperatures up to 199.9°C or °F and logged data.

Configuration Options

The series includes four primary models, each configured for specific sensing needs:

• OM-71: Temperature data logger with display; powered by a 3V CR2032 lithium battery.
• OM-72: Temperature data logger with display and remote temperature sensor; powered by a 3V CR2032 lithium battery.
• OM-73: Temperature/humidity data logger with display; measures relative humidity from 0 to 99% RH non-condensing. Powered by a 3V CR2032 lithium battery.
• OM-74: Thermocouple data logger with display supporting K, J, E, N, T, S, R, B, and C types. Includes a free 1 m (40") Type K insulated beaded wire thermocouple with subminiature connector and wire spool caddy. Powered by three AAA batteries.

All models feature an LCD real-time display showing time, date, alarm status, and battery condition. Data transfer is handled via a USB 2.0 Interface for fast data retrieval to PC software that supports graphing, zooming, autoscaling, and export to text or Excel formats.

Key Product Differences

The OM-71, OM-72, and OM-73 share identical physical dimensions of 6 H x 5.7 W x 1.3 cm D (2.36 x 2.24 x 0.51") and weigh 91 g (3.2 oz). The OM-74 is larger at 7.4 H x 5.5 W x 3.0 cm D (2.25 x 2.15 x 1.2") but lighter at 62 g (2.2 oz).

Storage temperature limits differ by model: -40 to 77°C (-40 to 170°F) for OM-71, OM-72, and OM-73; -30 to 80°C (-20 to 175°F) for OM-74. NIST calibration certificates are available as options (e.g., OM-74-NIST, OM-71-NIST). The series carries CE Mark certification.