or at least a strong table salt solution. Not distilled water. (ref. pH and ORP
Practices, pg. 24)
IV.
SPECIFIC RECOMMENDED MEASURING
P R O C E D U R E S
If the proper solution is not selected (KCl, NaCl, 442 or USER), see
Solution Selection, Pg. 11.
N O T E : After sampling high concentration solutions or temperature
extremes, more rinsing may be required. When sampling low conductivity
solutions, be sure the pH cap is well seated so no solution washes into
the conductivity cell from around the pH cap.
A. Measuring Conductivity/Total Dissolved Solids (TDS)
1.
Rinse cell cup 3 times with sample to be measured. (This
conditions the temperature compensation network and prepares
the cell.)
2.
Refill cell cup with sample.
3.
Press
or .
4.
Take reading. A display of [- - - -] indicates an overrange
condition.
B. Measuring Resistivity
Resistivity is for low conductivity solutions. In a cell cup the value may drift
from trace contaminants or absorption from atmospheric gasses, so
measuring a flowing sample is recommended.
1.
Make sure pH protective cap is secure to avoid contamination.
2.
Hold instrument at 30° angle (cup sloping downward).
3.
Let sample flow continuously into conductivity cell with no
aeration.
4.
Press key; use best reading.
N O T E : If reading is lower than 10 kilohms display will be dashes: [ - - - - ].
Use Conductivity.
C. Measuring pH
1.
Remove protective cap by squeezing its sides and pulling up.
10
COND
R E S
T D S
2.
Rinse sensor well 3 times with sample to be measured. Shake
out each sample to remove any residual liquid.
3.
Refill sensor well with sample.
4.
Press .
5.
Take reading.
6.
IMPORTANT
: After use, fill pH/ORP sensor well with Myron L
Storage Solution, a strong KCl solution or pH 4 buffer, and
replace protective cap. Do not allow pH/ORP sensor to dry out.
N O T E
: If none of the above are available, use a saturated solution of
table salt and tap water (ref. Cleaning pH/ORP Sensors, pg. 25).
D. Measuring ORP
1.
Remove protective cap by squeezing its sides and pulling up.
2.
Rinse sensor well 3 times with sample to be measured. Shake
out each sample to remove any residual liquid.
3.
Refill sensor well with sample.
4.
Press .
5.
Take reading.
6.
IMPORTANT
: After use, fill pH/ORP sensor well with Myron L
Storage Solution, a strong KCl solution or pH 4 buffer and
replace protective cap. Do not allow pH/ORP sensor to dry out.
N O T E
: If none of the above are available, use a saturated solution of
table salt and tap water (ref. Cleaning pH/ORP Sensors, pg. 25).
V.
SOLUTION SELECTION
A. Why Solution Selection is Available
Conductivity, Resistivity, and TDS require temperature correction to 25°C
values (ref. Standardized to 25°C, pg. 29). Selection determines the
temperature correction of conductivity and calculation of TDS from
compensated conductivity (ref. Cond. Conversion to TDS, pg. 32).
B. The 4 Solution Types
On the left side of the display is the salt solution characteristic used to
model temperature compensation of conductivity and its TDS
11
O R P
pH
