Carl Roth COND 50 VioLab, Instruction Manual

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21
UM Serie 50VioLab EN rev.1 19.05.2020
EN

ORP automatic calibration
Automatic calibration with 475 mV

In ORP measurement mode press the key to enter the calibration mode.

The string “POINT ORP 475” appears on the display; the device requires 475 mV as calibration point.

Rinse the electrode with distilled water and gently dab it with paper towel. Dip the electrode in the
475 mV Redox buffer solution.

When the solution is recognized and the signal is stable, the red stripes are replaced by the stability
icon .

Press the key as indicated by the string “PRESS OK”.

The actual measured value flashes on the display and then the beaker icon appears at the bottom
left, indicating that the instrument is calibrated. The instrument automatically returns to measure
mode.
ATTENTION: Before proceeding with the sensor calibration operations, carefully consult
the safety data sheets of the substances involved:

Redox Standard solutions.

STORAGE solution for ORP electrodes.

Filling solution for ORP electrodes.
Conductivity Parameter
COND 50 VioLab, PC 50 VioLab
Connect the Conductivity probe to the BNC type connector marked in grey, while the temperature probe
must be connected to the RCA / CINCH Temp connector always on a grey background.
Conductivity is defined as the ability of the ions contained in a solution to conduct an electric current. This
parameter provides a fast and reliable indication of the quantity of ions present in a solution.

…how to get Conductivity?
The first Ohm's law expresses the direct proportionality in a conductor between the current intensity (I) and
the applied potential difference (V) while the resistance R represents the proportionality constant.
Specifically: V = R x I, the resistance is consequently R = V / I.
Where R=resistance (Ohm) V=voltage (Volt) I=current (Ampere).
The inverse of the resistance is defined as conductance (G) G = 1 / R and is expressed in Siemens (S).
Measuring resistance or conductance requires a measuring cell, which consists of two opposite charge
poles. The reading depends on the geometry of the measuring cell, which is described through the constant
cell parameter C = d / A expressed in cm
-1
where d represents the distance between the two electrodes in
cm and A their surface in cm
2
. Conductance is transformed into specific Conductivity (k), which is
independent of the cell configuration, multiplying it by the cell constant. k = G x C is expressed in S / cm
even if the units of measurement mS / cm are in common use (1 S/cm -> 10
3
mS/cm) and µS/cm (1 S/cm ->
10
6
µS/cm).

Setup for Conductivity Parameter

In measure mode press button to access the SETUP menu.

Use the directional keys to move to COND SETTINGS P3.0 and access the menu by pressing the key
.

Move with the keys and to select the program to access.