18
7+Series Version 2.0
Conductivity electrode maintenance
Always keep the conductivity electrode clean. Before taking a measurement, rinse the electrode in pure water and
then rinse it in the sample solution. When submerge the electrode in solution, stir the solution briefly to eliminate air
bubbles and allow it to stay until a stable reading is reached. For conductivity electrode which keeps dry, soak the
electrode in pure water for 5-10 minutes. Rinse the electrode in pure water after measurement.
If the electrode coated with platinum black is invalid, immerse it in 10% nitric acid solution or 10% hydrochloric acid
solution for 2 minutes, then rinse the electrode in pure water. If the electrode still does not work, re-coat platinum
black, or replace with a new conductivity electrode.
Relations between TDS and conductivity
TDS and conductivity is linear related, the conversion factor is 0.40-1.00. Adjust per parameter P3.1. The factory
default setting is 0.71. The meter can only be calibrated in Conductivity mode and not TDS mode. After
calibration of conductivity, the meter can switch from conductivity to TDS.
Adjust TDS conversion factor per parameter P3.1 according to the data collected during testing
Common used TDS conversion factors
Conductivity of solution
TDS conversion factor
0-100 μS/cm
0.60
100-1,000 μS/cm
0.71
1-10 mS/cm
0.81
10-100 mS/cm
0.94
Setup Menu
Main menu
In the measurement mode, press
key to enter in P1.0, then press
and
to slide the main menu:
P1.0→P2.0→P3.0→P6.0.
P1.0
: pH parameter setting menu,
P2.0
: Conductivity parameter setting menu,
P3.0
: TDS parameter setting
P6.0
: Basic parameter setting menu.
Submenu
In P1.0 mode, press
key to enter in submenu P1.1 of pH parameter setting, then press
and
keys to
switch among submenu:
P1.1→P1.4→P1.5→P1.6→P1.7
.
In P2.0 mode, press
key to enter in submenu P2.1 of conductivity parameter setting, then press
and
keys to switch among submenu:
P2.1→P2.2→P2.5→P2.6→P2.8→P2.9
.
In P3.0 mode, press
key to enter in submenu P3.1 to adjust TDS factor.
In P6.0 mode, press
key to enter in submenu P6.1 of basic parameter setting, then press
and
keys to
switch among submenu:
P6.1→P6.6→P6.8
.
