User Guide
6362
ACCESSORIES
pH CALIBRATION SOLUTIONS
HI 7004M pH 4.01 Buffer Solution, 230 mL
HI 7004L pH 4.01 Buffer Solution, 460 mL
HI 7004/L pH 4.01 Buffer Solution, 1 L
HI 7007M pH 7.01 Buffer Solution, 230 mL
HI 7007L pH 7.01 Buffer Solution, 460 mL
HI 7007/L pH 7.01 Buffer Solution, 1 L
HI 7010M pH 10.01 Buffer Solution, 230 mL
HI 7010L pH 10.01 Buffer Solution, 460 mL
HI 7010/L pH 10.01 Buffer Solution, 1 L
ORP SOLUTIONS
HI 7020M 200-275 mV Buffer Solution, 230 mL
HI 7020L 200-275 mV Buffer Solution, 460 mL
HI 7091M Pretreatment Reducing Solution, 230 mL
HI 7091L Pretreatment Reducing Solution, 460 mL
HI 7092M Pretreatment Oxidizing Solution, 230 mL
HI 7092L Pretreatment Oxidizing Solution, 460 mL
ELECTRODE STORAGE SOLUTIONS
HI 70300M Storage Solution, 230 mL
HI 70300L Storage Solution, 460 mL
ELECTRODE CLEANING SOLUTIONS
HI 7061M General Cleaning Sol., 230 mL
HI 7061L General Cleaning Sol., 460 mL
HI 7073M Protein Cleaning Sol., 230 mL
HI 7073L Protein Cleaning Sol., 460 mL
HI 7074M Inorganic Cleaning Sol., 230 mL
HI 7074L Inorganic Cleaning Sol., 460 mL
HI 7077M Oil & Fat Cleaning Sol., 230 mL
HI 7077L Oil & Fat Cleaning Sol., 460 mL
REFILL ELECTROLYTE SOLUTIONS
HI 7071 3.5M KCl+AgCl Electrolyte, 4x50 mL, for single junction elec-
trodes
HI 7072 1M KNO
3
Electrolyte, 4x50 mL
HI 7082 3.5M KCl Electrolyte, 4x50 mL, for double junction electrodes
pH mV pH mV pH mV pH mV pH mV
0 990 1 920 2 860 3 800 4 740
5 680 6 640 7 580 8 520 9 460
10 400 11 340 12 280 13 220 14 160
Reducing pretreatment: immerse the electrode for a few min-
utes in HI 7091.
Oxidizing pretreatment: immerse the electrode for a few min-
utes in HI 7092.
If the pretreatment is not performed, the electrode will take
significantly longer to respond.
As with pH electrodes, gel-filled redox electrodes are more
suitable for industrial applications due to lesser mainte-
nance requirements. However, if working with refillable
electrodes, the electrolyte level should not fall more than
2½ cm (1") below the fill hole and topped up if necessary.
Use HI 7071 Refill Solution for single junction and HI 7082
for double junction electrodes.
In the event that measurements are performed with solutions
containing sulfides or proteins, the cleaning of the diaphragm
of the reference electrode must be performed more often to
maintain the proper functioning of the ORP electrode. There-
fore, immerse it into HI 7020 and measure the response; the
obtained value should be within 200 and 275 mV.
After this functional test, it is suggested to wash the electrode
thoroughly with water and proceed to the oxidizing or reduc-
ing pretreatment before taking measurements.
When not in use, the electrode tip should be kept moist and
far from any type of mechanical stress which might cause
damage. This can be achieved by installing the electrode in
such a way that it is constantly in a well filled with the sample
(stream or tank). The protective cap can also be filled with HI
70300 Storage Solution if the electrode is not being used at
all.
Note With industrial applications, it is always recommended to
keep at least one spare electrode handy. When anomalies
are not resolved with a simple maintenance, change the elec-
trode to see if the problem is alleviated.










