Sample Point Selection Guidelines
The sample must be taken at a point after the chlorine has been thoroughly mixed and has had time
to react completely with the process water. The sample line should be run with 3/8” diameter tubing to
minimize lag time between the process water and analyzer.
The sample point should always be located as close to the analyzer as possible so that the residual
chlorine in the water sample at that point is essentially the same as that in the analyzer flow cell.
A sample point that is too close to the chorine injection will deliver a sample that is not mixed adequately
or has not had sufficient time to complete the chemical reaction, thereby producing inaccurate readings.
Sample Line
When installing the sample line into the larger process pipe, use corrosion resistant brass or plastic
fittings only. The sample tap should be installed into the center of the pipe from either the top or side to
minimize chance of introducing air bubbles or sediment into the analyzer.
A sample valve upstream of the sample flow cell inlet tubing is required. We suggest using a metering
ball valve, needle valve or globe valve. If pressure exceeds 15 PSI, a pressure reducing valve is
required.
Sample Flow
Ensure that the water sample line is capable of delivering a continuous flow between 150 and 1000 ml
per minute to the sample valve at approximately 15 psi. If pressure exceeds 50 psi, use an auxiliary
water pressure reducing valve. If necessary, due to a long tubing run, increase the flow to the sample
flow cell to reduce the water sample transport time.
Consistent flow is critical to accurate measurement. A change in flow rate during operation of a calibrated
analyzer will require a recalibration of the analyzer. It is preferred to install a pressure regulator and
flow control valve to ensure a consistent flow. The part number FX-1000p-RM is available to control
the sample flow and pressure into the analyzer.
Dirty water applications require a flushing wye strainer to remove particulates from the sample.
Installation
10
FX-1000p
