EC500 V2.3 3/08

6

Changing Measurement Function

The meter can be set to measure pH, Conductivity, TDS or Salinity.

To change the mode:

1. Press and Hold the MODE/HOLD button for 2 seconds and the display will begin to

scroll through the units.

µS (Conductivity); pH; ppm S (Salinity); ppm (TDS); mg/l (TDS);

Note: The “HOLD” function cannot be on when changing the measurement function. If

“HOLD” is displayed in the lower left corner of the display, briefly press the MODE/HOLD

button to turn it off.

2. When the desired units are displayed, release the MODE/HOLD button.

TDS Compensation Ratio

The TDS value is determined by multiplying a conductivity reading by a known ratio

factor. The meter allows for selecting a conversion ratio in the range of 0.4 to 1.0. The

ratio varies with the application, but is typically set between 0.5 and 0.7.

Note: The stored ratio will briefly appear in the lower temperature display when the meter

is first turned on, or when changing measurement function to TDS.

Note: In the Salinity mode the ratio is fixed at 0.5.

To change the ratio, while in the TDS measurement mode (ppm or mg/l):

1. Press and release the CAL/RECALL button twice in succession.

The stored ratio will appear in the display.

2. Press the MODE/HOLD button to increase the ratio value in steps of

0.1.

3. When the desired ratio is displayed, press and release the

CAL/RECALL button to store the value and return to the normal

mode.

4. If no buttons are pressed for 5 seconds, the meter returns to measure mode.

Storing Readings

1. Press the MODE/HOLD button to store a reading. The storage

location number will be displayed on the lower display, while the

main display shows the stored reading. The meter will enter the

HOLD mode and the “HOLD” indicator will appear.

2. Press the MODE/HOLD button again to exit the HOLD mode and

return to normal operation.

3. If more than 25 readings are stored, previously stored readings

(starting with number 1) will be overwritten.