Xylem H-312-22 - Manual (Page 5)

Chapter 1
Introduction
H-312
Introduction 1-1
1.0 Introduction
The W ATER LOG ® H-312 is a submersible pressure transducer specifically designed for water
level monitoring. The H-312 is easy to use and works with any SDI-12 data recorder. The
“Serial-Digital Interface” is ideal for data logging applications with the following requirements.
Battery powered operation with minimal current drain
Pressure measurement data is transmitted digitally over long cable lengths without error
Multiple sensors on a simple three-wire cable
Up to 250 feet of cable between a sensor and the data recorder
(Use of H-423, SDI-12 to RS485 converter extends the range to 1000's of feet)
The H-312 has the following features:
Simple to install, use, and maintain (no on-site calibration required)
Performs extremely accurate measurements.
Linear deviation is less than 0.05%
Resolution is 1 part in 1,000,000
Accuracy over temperature range exceeds ±0.02 ft. of water
Enclosure is nonconductive and corrosion proof
Stainless steel sensor diaphragm
Sensor cable has internal atmospheric vent for compensation of barometric pressure changes
Junction box provides access for inspection and maintenance of dry-air desiccant
Low current operation (less than 150 microamps typical standby)
Suspension bail provides positive control of the sensor depth independent of temperature and
age dependent changes to the sensor cable.
Extended SDI-12 commands for setting the Stage to the current water elevation.