HF scientific 19944 Triple Validation Turbidimeter - 0-100 NTU - Manual (Page 14)

TVT2 (5/02)
Rev. 1.7 (.pdf) 9
In certain instances, during normal operation, the instrument will display a row of dashes
across the upper row of the display
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 ensure that the sample does not have a large amount of bubbles present; if
there are not bubbles present, 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 output and the
timed digital output (if selected).
4.2 Security Access Feature
The instrument is equipped with a security access code feature that can be activated in the
configuration mode. If the security feature is enabled, the screen shown in the illustration
below will appear when you press the MODE button.