eutech-instruments carbon dioxide gas Manuel D’Utilisation

Instruction Manual 

 

Carbon Dioxide Electrode

 

 

5

2. 

Using a pipet, add 1 ml of 0.1M or 1,000 ppm standard into the solution. When the reading 
has stabilized, record the mV value. 

3. 

Using a pipet, add 10 ml of the same CO

2 

standard used above to the beaker. When the 

reading has stabilized, record  the mV value.  

 
4. 

Determine the difference between the two readings. The electrode is operating correctly if 
a difference of 56 

± 3 mV is found, assuming the solution temperature is between 20

o 

and 

25

o

C. See the 

 section, if the change in potential is not within this 

range. 

 

Slope is defined as the change in potential observed when the concentration changes by a factor of 
10. 
 

(Check electrodes each day) 
 

1. 

Prepare standard carbon dioxide solutions whose concentrations vary by tenfold. Use 
either the 0.1M or 1,000 ppm carbon dioxide standard. Use the serial dilution method for 
this preparation. 

 
2. 

To a 150 ml beaker, add 100 ml of the lower value standard and 1 ml of ISA. Place the 
beaker on the magnetic stirrer and begin stirring at a constant rate. Lower the electrode tips 
into the solution. Assure that the meter is in the concentration mode. 

 
3. 

Adjust the meter to the concentration of the standard and fix the value in the memory 
according to the meter manufacturer's instructions. Rinse the electrodes with distilled water 
and blot dry. 

 
4. 

To another 150 ml beaker, add 100 ml of the higher value standard and 2 ml of ISA.  Place 
the beaker on the magnetic stirrer and begin stirring at a constant rate. Lower the electrode 
tips into the solution. 

 
5. 

Adjust the meter to the concentration of the standard and fix the value in the memory. 
Read the electrode slope according to the meter manufacturer's instructions. Correct 
electrode operation is indicated by a slope of 90-100%. See the 

 

section if the slope is not within this range. 

 

 
Samples should be measured immediately after collection. Samples should be stored according to 
the directions given in 

 if immediate measurement is not possible. 

 
The ratio of surface area to volume in the beaker should be minimized. Beakers containing the 
samples or the standard should be kept covered between measurements. 
   
Carbon dioxide buffer should be added just before measurement.