HF scientific MicroTOL Online Turbidimeter old series- 0-1000 NTU User Manual

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MICRO TOL (12/04)
Rev. 2.7

Select the desired offset level using the

t and u

buttons. Once you have set the

desired level, press the

↵ button to accept it.

7. This completes the offset configuration.
8. At this point, the instrument will continue to the configuration (CONFIG) mode of

the instrument or press MODE/EXIT to return to the AUTO mode.

6.1 Indexing Calibration Cuvettes
To achieve the greatest accuracy, and account for normal scratches and aberrations in
cuvette glass when calibrating, HF scientific inc. recommends indexing the cuvettes.

Each instrument is supplied with a white Indexing Pin located in the collar around the
optical well. Standards and standard kits purchased from HF scientific are supplied with
indexing rings.

The following two steps allow repeatable indexing of calibration standards:

1. Slowly rotate the standard, inside the optical well, one complete revolution (360º).

While rotating the standard slowly, observe the measured turbidity and locate the
position of the cuvette having the lowest reading.

2. With the calibration standard positioned at the location having the lowest turbidity

reading, install the Indexing Ring over the black light shield on the standard so that
the pointer of the Indexing Ring aligns with the Indexing Pin.

6.2 Restoring Factory Settings
If the instrument is unable to perform a calibration due to a low lamp output or a
calibration using the wrong standards, the instrument will display CAL on the lower row
of the display. The operator has two choices to correct this problem. If the operator can
determine whether a poor calibration or a low lamp caused the problem, he/she can
remedy the problem and recalibrate. If all else fails, the operator may restore the factory
calibration by performing the following operation. While in the AUTO mode, Push and
hold the

tbutton. Now push and release the ↵ then thetbutton. Factory calibration and

factory configuration have now been restored.

Note: Restoring the factory settings allows the use of the Micro TOL with reduced

accuracy. The original problem still exists and must be determined and corrected
before accurate operation of the Micro TOL will be resumed.