AccUView LED (1/2020)
Rev 2
9
4.0 Operation
This process monitor allows for the measurement of the transmittance of process water on-
line. Process water is usually reported in units of %T. Readings above 102 %T are
indicated by a flashing display. Readings above 100 %T indicate that the current sample is
better than the calibration water. Readings above 110 %T are not possible. All readings
are path length corrected to 10 mm.
Alternately measurements can be taken in Absorbance. Negative Absorbance readings
indicate the need for a calibration or that the water tested is better that what the instrument
was calibrated to. These readings show ABS on the lower line of the display. All readings
are path length corrected to 10 mm
During normal operation, the instrument will have the arrow beside
AUTO
. The scale (%
T or ABS) is displayed on the lower row of the display and the measured reading on the
upper row of the display (see illustration below). The user needs to keep in mind that the
instrument only updates at periods determined in the configuration or
CONFIG
menu.
Refer to section 7.14
Lamp Duty Cycle
.
4.1 Warm-up
Upon power-up the AccUView LED will require a warm-up period of about 30 minutes.
For improved accuracy, allow the AccUView LED to compete warm-up time prior to
calibrating. During the warm-up period, the display may flash indicating that it has
detected a temperature change. It is normal for this to occur during the warm-up period
4.2 Routine Measurement
The following steps describe how to measure the % T or ABS of a sample using this
instrument:
1.
Apply power to the instrument and allow the unit an initial warm up of 30 minutes.
2.
When a continuous process stream is flowing through the instrument, the instrument
will display the measured % T or ABS level of the sample by displaying it on the LCD
screen. In addition, the equivalent signal is provided on the analog (4-20 mA) output,
or the digital output, depending on the options selected.
A flashing display may occur after warm-up. This is an indication that either the
ambient or the water temperature or has changed rapidly. During this time the
readings may be slightly out of the specified accuracy. The AccUView LED will
automatically compensate as soon as the rate of temperature change slows.
