HF scientific MicroTOL Online Turbidimeter old series- 0-1000 NTU - Manual (Page 16)

MICRO TOL (12/04)
Rev. 2.7 10
4.0 Operation
This process turbidimeter allows you to measure the turbidity of your process water on-
line. The turbidity of the process water is reported in Nephelometric Turbidity Units
(NTU). Readings above 1000 NTU are outside the range of this instrument.
During normal operation, the instrument will have the arrow beside AUTO highlighted
with the current scale displayed on the lower row of the display and the measured reading
on the upper row of the display (see illustration below).
In certain instances, during normal operation, the instrument will display a row of dashes
across the upper row of the display (see illustration below).
This indicates that either the instrument is performing an auto-ranging function, or the
sample has a substantial amount of bubbles. If the dashes remain for an extended period
of time, please remove the flow through cell and check the sample for a large amount of
bubbles present. If the problem persists, please contact the HF scientific, inc. Technical
Services Department for further assistance and guidance.
4.1 Routine Measurement
The following steps describe how to measure the turbidity of a sample using this
instrument:
1. Apply power to the instrument and allow the unit to warm up (typically 45 minutes –
1 hour on initial commissioning).
2. When a continuous process stream is flowing through the instrument, the instrument
will display the measured turbidity 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.