HF scientific MicroTOL Online Turbidimeter - Manual (Page 13)

MICRO TOL (5/10) 7
Rev. 4.8
3.2.1 Drain Vent: The Micro TOL has been fitted with a drain vent in the “OUT”
bulkhead fitting. This fitting allows for atmospheric equalization, thus helping to alleviate
bubble formation in the cuvette. Refer to Figure 4.
Upon initial flow minor leakage may occur through the drain vent. This will subside once
normal flow is established.
For some high pressure systems, where the vent hole continuously leaks, a 6:32 seal screw
is provided which should be inserted into the vent hole and tightened.
The sensor drain tubing MUST be routed to a suitable drain. DO NOT reintroduce the
drain sample to the process stream. This is due to the fact that the wetted materials are not
FDA approved. See below for more information.
3.2.2 Wetted Materials: HF scientific accepts no responsibility for damage caused by
the introduction of vapors, fluids or other materials into the instrument process stream
which is not compatible with the instrument’s wetted materials. A list of the wetted
materials can be found in the specifications on page 1 of this manual.
3.3 Electrical Connections
All of the electrical connections to the instrument are made through the field terminal box,
which should be located directly under the sensor portion of the instrument. The
connections are labeled within the terminal box and are self-descriptive (see Figure 5).
Please follow all local and government recommendations and methods for installation of
electrical connections to and between the instrument and other peripheral devices.
Plugs are inserted into the alarm and 4-20mA/RS-485 cable bulkheads when shipped, to
ensure a watertight seal. These plugs should be removed and discarded when cabling to
either of these connections.
The power cable bulkhead will accept cable diameters from 5.8mm (.230 in.) up to 10 mm
(.395 in.). All terminals are designed to accept wires in the range of 14-28 AWG. All
wires should be stripped to a length of 6 mm (¼”). A strain relief strap is provided to
reduce tension on the power terminals.
It is the user’s responsibility to assure that the watertight seal is maintained after the
terminal box has been wired for operation. If any of the bulkheads are not tightened
properly around a cable or plug, the ratings of the instrument will be jeopardized and there
is a possibility of creating a shock hazard.
Note: Only qualified electricians should be allowed to perform the installation of the
instrument as it involves a line voltage that could endanger life.