The locking modular INPUT connectors (front panel) connect to external
detectors. Each input has a SENSITIVITY adjustment that is used only with
the LIQUID-PAD Detectors. The sensitivity is factory set so that when the
detector is placed within one inch of the pump, less than one mL of
water-based liquid will trigger the detector. For other types of liquids, or to
change the sensitivity level, refer to the SENSITIVITY ADJUSTMENT
Section. Sensitivity adjustment may be required when operating with cables
longer than 3-1/2 feet or in a high-temperature, high-humidity environment.
The LIQUID-SENSOR Controller is housed in a slate gray ABS plastic
enclosure, with aluminum front and rear panels. The unit can be placed on a
flat surface, on a support platform or on the top surface of some
MASTERFLEX ®or other type pumps.
The LIQUID-PAD Detector Model 877-9500 (with cable) or Model 877-9501
(without cable), Figure 9, operates on a capacitance change principle. The
detector is designed to be placed under the pump. If a leak occurs in the
pump tubing, the liquid will fall on the top surface of the detector. When
sufficient surface area is moistened (less than 1 mL of water-based liquid
when using the factory sensitivity setting), the change in capacitance is
sufficient to activate the alarm circuits. The detector has a locking modular
type connector. The cable between the detector and the controller is 3-1/2
feet long with modular locking connectors on both ends. Ten-foot and
fifteen-foot accessory cables are available. Refer to APPENDIX A for pin
configuration for the cables when connecting other detector types.
A four-inch hook-and-loop fabric fastener strip allows for attachment of the
detector pad to a flat surface to prevent the detector pad from moving. The
detector pad can also be permanently mounted by attaching it to a flat
surfacewithtwo#4screws.Thescrewlocationsatthecornersofthedetector
padare indicated bytwocircular markers.Thedetector structurewillneedto
be punctured by the screw for permanent attachment.
8
Figure 9. LIQUID-PAD Detector Model 877-9501
