Lutron Electronics CL-2006 Operation Manual page 14

* Press " CAL Button " ( 3-5, Fig. 1 ) once, the
Display will show following text with flashing ( approx.
10 seconds ).
Then the Display will show :
Now the meter is finished the " Zero Chlorine "
calibration procedures and ready for " 1.00 ppm "
calibration procedures.
5) 1.00 ppm calibration
Refer to page 12, when finish the " Zero Chlorine "
calibration procedures and the Display show
The meter is ready for " 1.0 ppm " calibration.
CAL
0.0
1.00
CAL
1.00
CAL
flashing
ppm
ppm
ppm
12