Calibration Procedure of HACH Pocket Turbidimeter - Up To

1.0 BACKGROUND
Calibration Procedure of HACH Pocket Turbidimeter
1.1 The Turbidimeter needs to be calibrated when the measured value of a
standard turbidity solution (e.g. 20 NTU) is not within 5% of the expected
value, i.e not between 19 – 21 NTU.
1.2 This procedure can be followed by lab technicians who have some
knowledge and experience with using the HACH Turbidimeter.
2.0 REFERENCES
2.1 HACH Pocket Turbidimeter (Cat No. 52600-18) instruction manual.
3.0 APPARATUS
3.1 HACH Turbidimeter.
3.2 Sample Cells.
4.0 REAGENTS
4.1 Standard turbidity solutions of 1.0 NTU and 20 NTU.
5.0 PROCEDURE
5.1 Take 3 clean sample cells. Fill one with distilled water (treated water) and
the other 2 with pre-prepared turbidity standard solutions of 1.0 and 20
NTU. Make sure to label each cell correctly.
5.2 Insert the cell containing the distilled water into the cell compartment and
close the lid.
5.3 TURN ON the instrument by pressing the “Read” button.
5.4 Press and hold the “CAL” key then press the “Read” key.
5.5 Release both keys together. After a short delay “dA” will flash on the
screen with the alternating dark value (mostly 0.0).

Notes:
5.6 Press and hold the “Read” key until the reading is stable. Release the
“Read” key to accept this value.
5.7 Remove this solution from the cell compartment and insert the 1.0 NTU
solution. Close the lid.
5.8 Press “CAL” key until “C1.0” appears on the screen with alternating value
(normally 1.0 NTU).
5.9 Press and hold the “Read” key. When the reading is stable release the
key. The value will be accepted and stored.
5.10 Remove the 1.0 NTU solution from the cell compartment and insert the 20
NTU solution. Close the lid.
5.11 Press “CAL” key until “C20” appears on the screen with alternating value
(normally 20 NTU).
5.12 Press and hold the “Read” key until the reading is stable. Release the key
to save this value.
5.13 Press the “CAL” key to end calibration. “CLd” will be displayed on the
screen. NOTE: If E09 is displayed, then recalibrate the instrument.
If Error messages appear on the screen, check that the standards have been labeled
properly and repeat the calibration. The possible errors are listed with the corrective
actions on pages 32-36 of the instrument manual.

1.0 BACKGROUND
Calibration Procedure of Sension 156 – Conductivity
1.1 The conductivity meter needs to be calibrated when the measured value of a
standard conductivity solution (e.g. 1000 uS/cm) is not within ± 30 of the
stated value.
1.2 This procedure can be followed by lab technicians who have some
knowledge and experience with using the Sension 156.
2.0 REFERENCES
2.1 Sension 156 Portable Multiparameter Meter (Cat No. 54650-18) instruction
manual.
3.0 APPARATUS
3.1 Sension 156 meter.
3.2 Conductivity probe.
4.0 REAGENTS
4.1 Standard sodium chloride (NaCl) solution of 1000 uS/cm.
5.0 PROCEDURE
5.1 Turn on the meter and set it to the conductivity reading mode. Make sure the
unit is in uS/cm
5.2 Place the conductivity probe into the 1000 uS/cm solution. Avoid resting the
probe on the bottom or side of the container.
5.3 Press the “CAL” key.
5.4 If the value on the screen is 1000 ± 30 uS/cm, press enter.
5.5 The meter automatically calibrates itself and returns to the reading mode.

Notes:
5.6 If the value is not in the acceptable range, then use the number keys to
change the numeric value to 1000 uS/cm, then press enter key.
For more information/steps on the calibration procedure, please refer to pages 40-41 of
the instrument manual.

1.0 BACKGROUND
Calibration Procedure of Sension 156 – Dissolved Oxygen
1.1 This procedure can be followed by lab technicians who have some
knowledge and experience with using the Sension 156.
2.0 REFERENCES
2.1 Sension 156 Portable Multiparameter Meter (Cat No. 54650-18) instruction
manual.
3.0 APPARATUS
3.1 Sension 156 meter.
3.2 Dissolve oxygen probe.
4.0 REAGENTS
4.1 DO Electrolyte filling solution.
5.0 PROCEDURE
5.1 DO Probe Servicing
5.1.1 Unscrew the membrane protector from the membrane cap. Do not touch the
inside with your fingers.
5.1.2 Hold the unscrewed cap upside down, vertically, with the hole facing up.
5.1.3 Fill the cap about 2/3 with the DO electrolyte filling solution.
5.1.4 While still holding the 2/3 filled cap vertically, gently screw back the DO probe.
The electrolyte should leak out from the thread else refill the solution and screw
back on again.
5.1.5 The probe is ready for use.

5.2 Calibration in Water Saturated Air
5.2.1 The DO probe to the meter Attach and turn on the instrument.
5.2.2 Prepare the storage and calibration chamber for calibration. This is the black
plastic tube with a small attached lid.
5.2.3 Open the small lid of the chamber and insert a wet-soaked sponge. A dry
compact sponge is provided with the supplies. Wet this with distilled water and
insert.
5.2.4 Insert the DO probe into the calibration chamber. The tip of the probe should not
be flooded with water. Ensure not to over wet the sponge.
5.2.5 Let the DO probe inserted in the chamber stand for 10 minutes.
5.2.6 Press the DO key to put the meter in the DO reading mode.
5.2.7 Press the “CAL” key.
5.2.8 The display will show 100%. Press the enter key.
5.2.9 The stabilizing icon will appear while the meter completes the calibration.
5.2.10 When calibration is complete, the meter will return to the reading mode.
Notes:
For more information/steps on the calibration procedure, please refer to pages 50-55 of
the instrument manual.