NEP-9500 MANUAL V1.01
Observator Instruments V1.01
Copyright 2017
©
Page 16
Physical cabling considerations
Cable normally supplied with the ANALITE NEP-9500 series probes is a specially selected PUR
sheathed and screened cable selected for strength, chemical resilience and exceptional resistance
to cuts, nicks and abrasion. The cable part number is NEP-CBL.
Nevertheless, care should be taken during the installation process of the probe and its cabling
ensure that the cable is not subjected to persistent pulling, snagging abrasion or severe
compression.
This is particularly important for the probes with fixed and glanded cable as any water penetration
through the cable sheath may find its way into the probe proper affecting the accuracy of the
readings and possibly causing irreparable damage.
For probes fitted with connectors, care must be taken to ensure the connectors are properly mated
to ensure a seal yet not screwed together too tightly so as to make their disconnection difficult after
a long deployment.
Prior to mating make sure both the probe and cable connectors are dry in the termination area
otherwise erratic operation may occur due to moisture.
Miscellaneous
The wiper on the NEP-9500 probes can be actuated by momentarily connecting the Wipe conductor
(5) to the Power Common conductor (0) for longer than 50msec.
This protocol can be implemented using a mechanical switch arrangement or open collector (drain)
output available on most loggers. For multiple wipes each consecutive wipe must be actuated after
the wiper has parked in its rest position (approx.. 8 seconds after a wipe actuation). Wipe pulses
applied during a wipe action will be ignored.
Note: During
the wipe period the NTU output will be held at the value measured just prior to the wipe
(within 2%).
The recommended external wiper activation interface arrangements are shown schematically below:
+3.6V
