eutech-instruments alpha ph differential probe User Manual

Instruction 

manuals 

 

         ECFP21A1A1 

 

 

 

13

 

 

4.2.1. If the sensor head has been cleaned

(see section 4.1.2) and calibration cannot 
be achieved, replace the salt bridge and 

reference solution. 

 

4.2.2. Hold the sensor firmly with the electrode 

tip facing upwards.  Remove the existing 
salt bridge by using a 15/16 wrench 

(24mm) and turning it counterclockwise.  
Dispose of the salt bridge using an 

approved method. 

 

4.2.3. Pour out the old reference solution.  

Rinse the reservoir with distilled or de-

ionized water. 

 

4.2.4.  Slowly fill the reservoir with reference 

solution so the solution just covers the 
reference O-ring. 

 

 

 

4.2.5. Slowly screw the new salt bridge clockwise onto 

the sensor head until secure.  Tighten the salt 
bridge with a 15/16 wrench (24mm) until snug. 

 

 

Do not over tighten. 
Maximum torque: 10 lbs

⋅in  (1.13 N⋅m) 

 
 

4.2.6. After replacing the salt bridge and reference 

solution, calibrate the sensor according to the 
instructions in the Alpha pH2000D controller 

manual.   

 

 

If after cleaning and refurbishment sensors still have slow responses, low measurement 
slopes or are seriously abraded or scratched they must be replaced.   

 

 

Do not over fill.  Overfilling will 

lead to excessive pressures that 
will affect the junction potentials of 

the reference. 

Figure 4.1: Replacing the salt bridge 

and reference solution