Hach REFO 3 Operating Instructions Manual page 19


Snap the cover onto the battery compartment again.

Entering standard number and calibration values
Standard number and calibration values need only be entered again if the standard is
changed. The 4-digit standard number and calibration values for 20°, 60° and 85° are
indicated on the rear of the standard they apply to.

Put REFO on the standard (remove cloth!)

Turn on REFO with key Meas/ON

Select program P3 with the program key

Press key Meas/ON to calibrate REFO. It identifies M- or D-mode automatically (not true
for REFO 3)
D0379 St - Nr

+1
Figure 4: Entering the standard number

Enter the 4-digit standard number (current digit blinks). Press the statistics key until the
correct digit appears.

Press the program key to skip to the second digit

Press the statistics key until the correct digit appears.
 Repeat the procedure for the 3rd and 4th digits.
When the fourth digit is entered, use the angle selector key to enter calibration values.
Every calibration value consists of four digits (in D-mode with one place after decimal
point, in M-mode without decimal point).
e.g. 85° = 99.5
1st digit = 0
2nd digit = 9
3rd digit = 9
4th digit = 5
To enter the calibration values for 20° press the statistics key until the correct digit ap-
pears

Press the program key to skip to the second digit

Press the statistics key until the correct digit appears.

Repeat the procedure for the 3rd and 4th digits.

Press the angle selector key to skip to calibration value 60°

Input procedure as explained above

Press the angle selector key to change to calibration value 85°
Angle Select
Program Key
Statistics Key
099.5
Figure 5: Entering the calibration values
Angle Select
85°

+1
Program Key
Statistics Key
5