Teledyne 4250, Installation And Operation Manual, Page: 91 / 204

3-1
4250 Flow Meter
Section 3 Installation
This section of the manual contains information on installing the
4250 Flow Meter. Included are sections on power sources,
mounting methods, interconnection wiring, installation of the AV
sensor and setup procedure for the unit.
3.1 Preparation for Use
The flow meter is shipped with a roll of paper installed and a
standard program in the system memory, called the
default
program. This program exists to test the flow meter at the
factory, and also because the computer must always have some-
thing programmed. You will usually program the flow meter dif-
ferently for your installation.
You should familiarize yourself with the programming procedure
and practice working through the program on the flow meter to
become comfortable with programming. You can program the
unit in the shop rather than at the job site, with the exception of
the level adjustment, if you want. This will minimize the possi-
bility of dirt and moisture getting inside the flow meter at the
installation.
3.1.1 Installing the
Desiccant Canister
If the unit is new, at this time you can install the desiccant can-
ister. It is provided in the accessory package and looks like a
small, flat can with little holes in it. Open the flow meter case lid.
Note the small clamp that resembles a bottle cap opener located
near the bottom right-hand corner of the case lid. Install the des-
iccant canister by pressing it under this bracket, with its viewing
window lined up with the circular hole in the bracket.
Make sure the clamp is fully engaged over the canister. The par-
ticles inside the desiccant window should be blue. If the particles
are pink, the desiccant is saturated and you need to regenerate it
before using it. If the unit has been in use and has been returned
for reprogramming, clean it and inspect it as outlined in Section
5 of this manual. You can also install the external desiccant car-
tridge, which provides pressure equalization for the AV sensor
pressure transducer.
3.1.2 Installing the External
Desiccant Cartridge
Snap the external desiccant cartridge into the clamps mounted
on the top of the cabinet. Then attach the silicone tubing between
the top of the desiccant cartridge and the black plastic elbow
fitting mounted on the side of the case near the top.
This desiccator keeps moisture out of the AV sensor’s reference
port. This port connects to a tiny tube that goes through the case
and the sensor cable all the way to the transducer. Like the case
desiccant canister, the external desiccant cartridge should be
colored blue. If it is violet or pinkish, you need to regenerate it.