HD9408.3B is a barometric transmitter that uses a piezoresistive high accuracy and temperature-compensated sensor. It allows measuring the atmospheric pressure in the range 0…1350 hPa (digital outputs) or 500…1200 hPa (analog outputs), providing extreme accuracy and time stability, with excellent repeatability, low hysteresis, and
excellent temperature behavior. The superior performances are obtained thanks to the employment of a piezoresistive Silicon sensor that integrates both a pressure sensitive as well as a temperature sensitive element. The measurement of pressure and temperature are processed by a microprocessor to obtain an output signal that is compensated over the transmitter’s whole, wide temperature operating range: -40…+85°C. The sensor is factory calibrated at several points at different temperatures in the range of use.
The transmitter is available in three versions which differ in the output type:
• HD9408.3B.1: configurable 0…5 V or 1…5 V analogue voltage output and digital RS232, RS422 or RS485 output. Standard MODBUS-RTU and NMEA 0183 protocols.
• HD9408.3B.2: active configurable 0…20 mA or 4…20 mA current output and digital RS232, RS422 or RS485 output. Standard MODBUS-RTU and NMEA 0183 protocols.
• HD9408.3B.3: digital SDI-12 output, compatible with version 1.3 of the protocol.
The digital output enables the transmission of the measurements over long distances and connects the transmitter to sensor networks. The pressure measured and transmitted with MODBUS RTU and SDI-12 protocols can be expressed in different user-selectable measuring units.
The watertight housing with IP 67 protection degree allows the use of the instrument even in harsh environments.
The instrument is particularly suitable for meteorological applications (AWOS – Automated Weather Observing Systems), environmental monitoring systems, meteorological and environmental data logging, measurement laboratories, atmospheric pressure compensation in the performance of internal combustion engines, barometric pressure compensation in clean rooms, vehicle emission test.
Its low power consumption makes it ideal for remote acquisition systems such as automatic weather stations powered by solar cells. DC power supply 10…30 Vdc.