The HDT uses a Xentaur Hyper-Thin-Film (HTF™) high capacitance aluminum oxide sensor with a measuring range of -76°F to 86°F (-60°C to +30°C) (dp). HTF™ sensors provide a degree of accuracy, speed of response and stability unavailable from instruments using conventional aluminum oxide or polymer sensors.
Sensor model XTR-60 is designed to work in tough, high pressure and even in liquid applications. The sensor is nonaffected by condensation and water slugs; once dried, it will resume measurement without requiring recalibration.
The model HDT is a HART compliant IP66/NEMA4X hybrid dew point transmitter, providing loop powered analog as well as a digital output. Housed in a 1.25"dia. stainless steel case it has an overall length of 5.68", including the standard industrial 9.4mm 4 pin connector. This makes the HDT the world's smallest dew point transmitter.
The instrument draws 4-20mA from the power supply. The 4-20mA is linear to °C(dp) with an output resolution of 0.1°C(dp) or 0.25uA, whichever is greater. The output range is programmable.
The instrument can supply a digital output by modulating the 4-20mA loop line. The interface is defined by HART. In the digital mode the HDT can be remotely operated and the dew point as well as temperature (and pressure if installed) can be read. In the digital mode multiple units can operate on the same loop cable as a multi-channel instrument. In this configuration each HDT draws only 4mA independent of the measured dew point
The HDT provides a factory programmable dew point alarm signal through a digital output pin. Additionally, relays or external devices can be operated through the analog or digital loops.
The HDT has two different thread types, which makes the upgrade of existing installations easy. The HDT connects through inexpensive two-conductor cables over long distances.
The HDT transmitter uses a multipoint calibration table which provides temperature compensated dew point readings for temperatures from +14°F to +158°F (-10°C to +70°C) (t). Thus, the HDT provides accurate dew point measurements over its full range even under extreme temperature conditions, such as when installed outdoors or close to heat sources.
