Emerson Rosemount TCL - 7.5 Configuring the measurement

For an explanation of terms, see Section 7.4.1 and Section 7.4.2.
6. To return to the main display, press MENU and then EXIT.
7.5 Configuring the measurement
7.5.1 Purpose
This section describes the following:
1. Program the transmitter to measure total chlorine. This step is necessary, because
the transmitter can be used with other sensors to measure other chlorine oxidants.
2. Set the level of electronic filtering of the sensor current.
3. Set the display resolution.
7.5.2 Definitions
Chlorine
oxidants
Although the TCL is used to measure total chlorine only, the Rosemount
1056 Transmitter used with the TCL can be used to measure other chlorine
oxidants, for example, monochloramine and free chlorine.
Filter
The transmitter applies a software filter to the raw sensor current. The
filter reduces noise but increases the response time. The available filter(s)
depend on the time setting. If the filter is between 0 and 10 seconds, the
transmitter applies a window filter. The window filter averages the
measured value within the filter time. For example, if the filter is 5 seconds
and a step increase is applied to the input, the displayed value increases
linearly, reaching the final value after 5 seconds. If the filter is set to greater
than 10 seconds, the transmitter applies either an adaptive filter or a
continuous filter. An adaptive filter discriminates between noise and real
process change. It filters changes below a fixed threshold value but does
not filter changes that exceed the threshold. It is best used in situations
where the noise is relatively low. A continuous filter dampens all changes.
The filter timer setting is approximately equal to the time constant, the
amount of time required for the reading to reach 63% of the final value
following a step change.
Resolution
If the chlorine concentration is less than 1.00 ppm (mg/L), the display
resolution can be set to 0.XX or 0.XXX.
7.5.3 Procedure - configuring the measurement
Complete the following steps to configure the transmitter to measure total chlorine.
1.
Press MENU.
The main Menu screen appears.
2. Move the cursor to Program and press ENTER.
Programming the transmitter
52 Rosemount TCL