Xylem WL550 OIL WATER INTERFACE METERS - Manual (Page 6)

Global Water
800-876-1172 • globalw.com
- 6 -
To turn off this feature or resume normal operation, simply hold down the start button
for at least 4 seconds.
If you hold down the start button for 4 seconds while the probe is not in a liquid, it will
signal that the probe is in the air and the signal will only stop once the probe is
immersed in a liquid.
V. Operating the unit in the field
The oil/water interface meter can be tested in most containers to detect water. It will
even detect distilled water that contains some dissolved solids. It is more sensitive
to water, since the pins are often coated with oil or product that coats the water
sensing pins. The unit will not typically detect product if there is more than low
ambient light conditions or a white container. This is completely normal and the unit
should NOT be recalibrated, since most wells are very deep and have very little
ambient light.
The water level meter is not as sensitive to water and will not usually detect
commercial quality distilled water.
It is possible to recalibrate the unit for very viscous oils, for a severely scratched
prism assembly or for very conductive water, for example brine or salt water
intrusions.
Adjustment of water sensitivity or hydrocarbon sensitivity
DO NOT CHANGE WITHOUT CALLING FOR TECHNICAL SUPPORT FIRST
There are two small potentiometers located on the circuit board. One is labeled
water. Turn clockwise for very pure/low conductivity water. For saltwater turn
counterclockwise. For white PVC casing or a heavily emulsified layer, turn the fluid
potentiometer counterclockwise. For highly viscous oils, turn the fluid potentiometer
clockwise. Before beginning field work, it is worthwhile to test the unit quickly in any
container to verify it will detect water. The unit will sound continuously if the battery
is low. Since the battery is easily changed without any tools, it is recommended that
a spare battery be included in the carry case/field kit.