Observator Instruments Analite NEP-9500-PLUS Series Manual page 18

3. In a simple application, the probe is simply immersed into the water to the desired depth, but within the
depth rating of the probe. Please note the depth rating is based on stagnant water.
4. Allowances must be made for the effect of flowing water to ensure the stagnant depth rating is not
exceeded. If the probe is to be installed downwards then it is recommended to install it a few degrees
away from the vertical to allow bubbles to escape away from the optic face.
5. Probes with integrated wiping should be installed such that they can be easily retrieved from time to
time to replace the wiper arm assembly.
6. It is important that the optic end of the probe is kept clear of obstruction such as the river/sea bed. The
minimum distance between the optic head and any object should be 50mm (2").
Be Careful: The standard casing of the NEP-9500, as well as the optic face, is made of plastic materials
and should be protected from accidental scratching or abrasion. The wiper arm assembly should be
replaced periodically to avoid abrasive material build-up in the pad that may eventually abrade the optic
face. The optic face is partially protected from damage by the protruding castellation in the probe casing.
If the probe body is to be installed in a glanded fitting (for insertion into a pipe, etc.) then care must be
taken to ensure the sealing surface pressures offered by the gland fitting are not excessive so as to not
cause distortion of the probe casing and force leakage. The NEP-9500 probes are thin wall instruments
and so glanding pressure must be minimal and spread over the largest possible area. Do not cut or
damage the outer sheath of the cable. Water may enter the probe through holes or cuts in the cable
sheath. Where damage may occur due to river rocks striking or rolling over the probe body, a protective
shroud should be used. Such a shroud not only protects the probe but also assists in maintaining a
minimum distance between probe optics and any local obstructions.
Manual | NEP-9500-PLUS series turbidity probe
Status: Final | Not confidential
Page 18 | 21
V20200309