HH804U 2 Channel RTD Thermometer w/Optional Datalogging Software
High Accuracy PT100 RTD Input Thermometers
Supported Applications
The Omega HH804 Series is a 4½-digit, compact, portable two-channel RTD thermometer with optional datalogging software, designed for accurate temperature measurement using external 100Ω platinum RTD sensors. It is well suited to laboratory, HVAC, and field measurement work where two independent temperature channels are useful.
Temperature indication follows the reference resistance tables for the common platinum-RTD curves: Pt385 (European curve, Alpha = 0.00385), Pt3926 (American curve, Alpha = 0.003926), and Pt3916 (Japan curve, Alpha = 0.003916).
Operating Conditions & Performance
The thermometer accepts external 100Ω platinum RTD sensors and measures over the following ranges:
• Pt385 (100Ω): -328°F to 1472°F (-200°C to 800°C).
• Pt3916 / Pt3926 (100Ω): -328°F to 1166°F (-200°C to 630°C).
Accuracy is ±(0.05% rdg + 0.2°C) on the °C scale and ±(0.05% rdg + 0.4°F) on the °F scale, with a display resolution of 0.1°C or 0.2°F and a reading rate of one measurement per second. The unit runs on four 1.5V AAA (UM-4/R03) batteries and weighs 260 g including batteries, in a 160 mm (H) x 83 mm (W) x 38 mm (D) housing.
• Operating ambient: 0°C to 50°C (32°F to 122°F), <80% R.H.
• Storage: -20°C to 60°C, <70% R.H.
• Sensor connection: 3-wire or 4-wire subminiature 4-prong connectors (flat blades spaced 7.9 mm center to center).
The series is CE marked and manufactured under an ISO 9001 certified system.
Configuration Options
The two models share the same dual-input RTD measurement platform and differ by regional configuration:
• HH804 — standard dual-input RTD thermometer.
• HH804U — the U-configured variant of the same instrument.
Both accept the Pt385, Pt3926, and Pt3916 curves and support optional datalogging software for recording measurements to a PC.
Key Product Differences
The series is ordered as HH804 with the variant suffix:
• HH804
• HH804U
Select the model that matches the required regional RTD curve and configuration; both provide the same two-channel measurement, accuracy, and optional datalogging capability.
| Additional Features 1 | MIN/MAX/REL/AVG/HOLD, Offset Adjustment, Auto power off, Hi -Lo Limit alarm |
| Battery Size and Type | Alkaline AAA |
| Display Type | LCD |
| Display Type Note | Dual 4 1⁄2 digit +Elapsed Time |
| Electrical Connection | 4-pin mini DIN (S-Video) |
| Form factor | Handheld |
| Measurement Type | Temperature |
| Number of Measurements | 2 |
| Operating Temperature, Max | 50 °C |
| Operating Temperature, Min | 0 °C |
| Series ID | HH804-805 |
| Supply Power Type | Battery |
| Temperature Accuracy | ± 0.05 % |
| Temperature Accuracy Note | Stated accuracy at 23°C ± 0.05%, <75% RH ± (0.05% rdg + 0.2°C) ± (0.05% rdg + 0.4°F) |
| Temperature Sensor Type | RTD |