HF scientific MicroTPI Field Portable Turbidimeter (Old) - Manual (Page 12)

2. While rotating the standard, observe the turbidity reading and locate the cuvette
position with the lowest turbidity reading.
3. 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 Ring aligns with the reference arrow on the instrument.
4.3 Calibration Procedures
1. Select the calibration function of the instrument by pressing the CAL button once.
The “CAL” block will be illuminated on the display with “1” indicating the standard
required for this step of the calibration. This is the first standard that should be used
in a full calibration.
2. Insert the 1000 NTU standard (CAL 1 in the figure above) into the sample well and
press down until the cuvette snaps fully into the instrument. Align the indexing ring
with the arrow on the instrument (see section 4.2 if you have not already indexed the
Standard).
3. Wait for the reading to stabilize. Once the reading has stabilized press the
↵
button
to indicate to the instrument that it should calibrate on this point. You will see
something similar to the display shown below.
4. When the instrument has completed calibration on this point, it prompts you to insert
the next calibration standard into the sample well (CAL 2).
5. Repeat steps 2-4 for each calibration standard. When you calibrate on CAL 4
(turbidity free water), the instrument will automatically exit out of calibration
returning back to the normal operating mode.
Notes :
1. During calibration, the screen actively displays the current turbidity value.
After the CAL value changes, it is common for the display to not report the exact
turbidity of the standard as it either is expecting a new standard or has not yet
calibrated the new standard.
2. If you wish to exit the calibration mode you may do so at the end of any step by
pressing the CAL button. The instrument will accept only the values calibrated
prior to exiting.
Ref. 22666 (12/04)
Rev. 1.4
8