HF scientific Micro1000 Laboratory Turbidimeter - 0-10,000 NTU - Manual (Page 12)

Rev. 3.2 6
During normal operation, the AUTO block will be highlighted with the current scale displayed on
the lower row of the display and the measured reading on the upper row of the display:
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
not yet stabilized (e.g. air coming out of solution in the form of bubbles). The dashes should remain
for a brief period of time (< 45 seconds). If the dashes remain for an extended period of time please
contact the HF scientific, inc. Technical Services Department for further assistance and guidance.
The following sections describe how to use the instrument under normal operating conditions.
These sections include details on how to take normal, routine turbidity measurements using the
instrument.
WARNING: NEVER pour liquid directly into the sample well of the instrument: always use a cuvette.
The instrument will accurately measure the turbidity of a sample using only cuvettes with the
black light shield on the cuvette (provided by HF scientific, inc.), the optional pour through
assembly, or the optional flow through assembly.
4.2. Grab Sample Measurement (Routine Measurement)
The following steps describe how to measure the turbidity of a grab sample using this instrument:
1. Turn on the instrument. The instrument will be in the normal operating mode. Allow instrument
to warm up for at least 30 minutes.
2. Sample approximately 100 ml of the process stream as you would normally do for turbidity
measurement.
3. Obtain a clean and dry sample cuvette.
4. Rinse the cuvette with approximately 20 ml of the sample water (2/3 of cuvette volume), capping
the cuvette with the black light shield (cuvette top) and inverting several times. Discard the 20
ml of used sample and repeat the rinsing procedure two more times.