Ohmic Instruments Co.

HT-737 Advanced Digital Transmitter
Packaged in a rugged housing, the HT-737 advanced digital transmitter measures relative humidity, temperature, dew point and absolute humidity. It features a programmable controller, digital zero and span adjustment, and RS-232 or RS-485 output capability. The HT-761 analog version provides a linear 0–1 VDC or 1–10 VDC output of ambient relative humidity and temperature over the range of 32–176°F.

Model AHT-200 Absolute Humidity Transmitter
The Model AHT-200 absolute humidity transmitter uses thermal conductivity sensors to measure moisture content at elevated temperatures up to 200°C. It is said to outperform conventional capacitive/resistance humidity sensors in harsh environments, and it can recover from exposure to deposits and condensation. Its range is 0–130 g/m3 with an accuracy of ±3 g/m3, which corresponds to ±2.3% RH at 35 g/m3 at 60°C.

Humidity Sensor Evaluator (Model HSE)
The Humidity Sensor Evaluator (Model HSE) displays, monitors, and logs relative humidity (RH) and dry-bulb and dew-point temperature readings of resistive and hybrid capacitive humidity sensors via a computer’s USB port. Its software includes RH sensor response curves for hybrid capacitive sensors, such as the manufacturer’s HC-610. It is compatible with Windows 2000, XP and Vista, and requires either a USB 2.0 or a USB 1.2 port. It includes a humidity/dew-point calculator, two relative humidity sensors, and a thermistor. The sensor chart display and logging functions allow the user to select °C, °F, K, or R as the units for temperature.