Hach-Lange 1720E Low Range Turbidimeter - Manual (Page 17)

13
Installation
3.3.1 Mounting the Turbidimeter Body
Locate the turbidimeter as close to the sampling point as possible. A shorter distance for
the sample to travel results in a faster response time.
Clean the turbidimeter body and bubble trap before installation using the instructions
supplied in
section 6.4.2 on page 26 . Slotted mounting brackets are integral parts of the
turbidimeter body. Install customer-supplied hardware appropriate for the installation
environment using the criteria detailed below:
• Install in a location that is isolated from vibration.
• Allow at least 22 cm (approximately 10 inches) clearance for removal of the head
assembly and bubble trap cover from the top of the turbidimeter body.
• Leave enough room below the turbidimeter body to remove the bottom plug and to
place a container under the drain when calibrating or cleaning.
Note: Make sure the top of the turbidimeter body is level.
• Install two ¼-20 bolts 10- 3 / 4 inches apart (on center). Leave at least ¼-inch of the bolt
head exposed.
• Make sure the bolts are installed level.
Slide the slotted mounting brackets of the turbidimeter body onto the bolts.
3.3.2 Installing the Head Assembly
After the turbidimeter body has been mounted, install the bubble trap cover, then place the
head assembly on the turbidimeter body with the label facing the front. Move the head
assembly back and forth slightly to ensure it is properly seated on the body of the
instrument. Failure to properly seat the head will result in light leakage and
erroneous readings.
The rear portion of the head assembly has a molded “lip” which may be used to hang the
head assembly on the turbidimeter body edge for routine maintenance.
3.4 Installing a Sample Line
DANGER
This turbidimeter is not designed for use in hazardous locations or with samples
that are flammable or explosive in nature. If any sample solution other than water is
used in this product, test the sample/product compatibility to ensure user safety
and proper product performance.
One-fourth inch OD rigid or semi-rigid tubing is recommended for sample lines. Run them
as directly as possible between the turbidimeter body and the sampling point to minimize
sample flow lag time.
Install sample line taps into larger process pipes to minimize interference from air bubbles
or pipeline bottom sediment. A tap projecting into the center of the pipe is ideal.
Figure 5
shows examples of sample tap installations.
Note: When setting the flow rate, take care to avoid sweeping air “micro-bubbles” through the
internal bubble trap. Observe the sample flow inside the turbidimeter body. If small air bubbles can
be seen flowing up through the center, reduce the flow rate.