HF scientific MicroTOL Online Turbidimeter old series- 0-1000 NTU User Manual
Page 14
MICRO TOL (12/04)
Rev. 2.7
8
3.2.1 Pressurized Systems: For pressurized systems, keep the pressure below 69 kPa (10
PSI) or 7.62 m (25 foot) of head or limit the flow the 1 liter per minute. An inline flow
regulator is available from HF scientific inc. catalog number 19778.
3.2.2 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.
In high-pressure systems, minor leakage may occur. This will subside once normal flow
is established.
For systems, where the “OUT” line does not return to an open drain, a 6:32 seal screw is
provided which should be inserted into the vent hole and tightened.
3.3 Electrical Connections
All of the electrical connections to the instrument are made through the field terminal
box, which should be located under the sensor section 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.