Specifications
18 
6.6  Configuration 
6.6.1  Selecting pH or ORP Mode of Operation 
The alpha pH 500 transmitter is not only a pH transmitter, but 
also  an  ORP transmitter. When  configured  to  measure  ORP, 
electrode must be changed and calibrated (see Section 5.3 for 
calibration  procedure).  ORP  values  are  measured  and 
displayed in mV only. 
1.  Press  ENT  key  and  use  ▲  or  ▼  keys  to  scroll  till  LCD 
displays „COF‟ (Configuration). Press ENT again. 
2.  LCD displays „PH‟. Transmitter is set to operate as a pH 
Transmitter.  Use  ▲  or  ▼  keys  to  change  from  „PH‟  to 
„ORP‟,  if  this  Transmitter  is  to  operate  as  an  ORP 
Transmitter. 
3.  Press the ENT key to accept selection. 
4.  Press  and  keys together, to return to MEAS mode. 
5.  If  the  readings  on the  Transmitter is  fluctuating  wildly,  please  proceed  to 
Section 6.6.2, for a possible solution. 
6.6.2  Selecting Asymmetrical or Symmetrical Mode of Operation 
In  some  applications,  there  may be  some  electrical  interference  in  the  sample, 
where the electrode is installed. The sensitive electrode picks up the signal and the 
effect is displayed on the LCD. 
If  the  electrical  interference  is  from  an  AC source,  the  readings  on  the  LCD 
fluctuates  wildly.  If  the source is  DC,  then  readings  will  be  stable,  but at a wrong 
value. 
In such cases, switch the Transmitter to the Symmetrical mode as below: 
1.  Press ENT key and use ▲ or ▼ keys to scroll till LCD 
displays „COF‟ (Configuration). Press ENT again. 
2.  LCD  displays  either  „PH‟  or  „ORP‟  depending  on 
requirement. Press ENT key. 
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