Xylem DH-21 - Manual (Page 9)

Chapter 1
Introduction
DH-21
Introduction 1-1
1.1 Overview of the “W ATER LOG”
The “ W
ATER LOG” Sensor/Logger, as shown in Figure 1-1, is an innovative water level
measurement system for use in ground and surface water measurement. Its design can eliminate
the need for an instrument shelter or other site improvements. You will find the “
W
ATER LOG”
very reliable and easy to use. The small cylindrical design fits well casings as small as 2 inches in
diameter. It can be deployed below ground surface to minimize temperature effects and
vandalism. The “
W
ATER LOG” is self-contained with batteries and a reliable non-volatile
FLASH EEPROM memory.
The 1/4" polyethylene tubing (vented cable) encloses the data cable and provides an atmospheric
vent for the sensor. Precautions should be taken to avoid kinks or leaks in the vented cable. A
kink in the vented cable would interfere with the atmospheric reference and cause errors in your
data. A leak would allow moisture to enter and damage the pressure transducer.
The “ W
ATER LOG” contains an internal dry air system which maintains the atmospheric
reference to the sensor and protects the sensor and electronics from moisture condensation.
The “ W
ATER LOG” comes with convenient user software which executes on any IBM
compatible computer. The software is used to initialize the “ W
ATER LOG” and configure it for
long term unattended data logging. It also is used to retrieve the data from the logger. The
retrieved data is stored in a convenient format for analysis using the
W
ATER WARE TM software
or commercial analysis software.
The “ W ATER LOG” is powered by a field replaceable “D” cell Lithium battery pack. It is a low-
power device and is designed to operate up to five years on the battery pack.