eutech-instruments iodide epoxy User Manual

Instruction Manual 

 

Iodide Electrode

 

 

5

6. 

Adjust the meter to the concentration of the standard and fix the value in the memory.  

 
7. 

Read the electrode slope according to the meter manufacturer's instructions. Correct 
electrode operation is indicated by a slope of 93-100%. See the 

sections if the slope is not within this range. 

 
 

MEASUREMENT 
 

 
All samples and standards should be at the same temperature for precise measurement. A difference 
of 1

o

C in temperature will result in about a 2% measurement error. 

 
Constant, but not violent, stirring is necessary for accurate measurement. Magnetic stirrers can 
generate sufficient heat to change the solution temperature. To counteract this effect, place a piece 
of insulating material, such as styrofoam sheet, between the stirrer and beaker. 
 
Always rinse the electrodes with distilled water and blot dry between measurements. Use a clean, 
dry tissue to prevent cross contamination. 
 
For samples with high ionic strength, prepare standards whose composition is similar to the sample. 
Dilute concentrated samples (>0.1M) before measurement. 
 
Use fresh standards for calibration.   
 
Use 2 ml of ISA for each 100 ml of sample or standard. 
 
Always check to see that the membrane is free from air bubbles after immersion into the standard or 
sample. 
 

 
All samples must be aqueous and not contain organics which can dissolve the epoxy electrode body 
and/or the cement bonding the sensing crystal to the electrode body. Infrequent measurements in 
solutions containing methanol, benzene, or acetonitrile are permitted. Highly polar solvents slowly 
attack the electrode. Please check with Eutech Instruments Pte Ltd. before using these electrodes in 
other organic solvents. 
 
The temperature of the sample solutions and of the standard solutions should be the same and below 
80

o

C. 

 
The pH range for the iodide ion electrode is 0-14. Neutralize samples outside this range with acid or 
base to bring them in range. 
 
Interferences should be absent. If they are present, use the procedure found in the 

Interference 

and 

 sections to remove them.