Question About TDS Pen
 

Say I Want To ask This I am Just Double Checking To Make Sure My TDs Pen is okay.. I Took It out the box today just to check it right.. well I turned it on and did the calibration steps, dipped in clean RO water and wiped it off and took Reading and it came out reading 1.. so is that okay? or do I have issues? I did exactly like this

https://www.youtube.com/watch?v=tqw6bKdWdL8