apex orp question

[johnston]

do you leave or remove the rubber cap at end of probe? mine has been on since start up and reads 284 if i remove it it drops to171 just not sure what to do and how to test accuracy thx for any help

 

[Sdot]

do you leave or remove the rubber cap at end of probe? mine has been on since start up and reads 284 if i remove it it drops to171 just not sure what to do and how to test accuracy thx for any help

Remove the rubber cap.