C
coconaut
SmokyMtnToker - you shouldn't be using RO water to test a pen. RO water has a pH of 7.
pH pens measure pH by sending an electrical current through the water. RO water has no minerals to conduct that current, so you will not get true readings.
On top of that, that little bulb on your pH pen contains some kind of solution, putting the pen in RO water can cause water to enter the bulb through osmosis. This will ruin the glass sensor.
Pens should always be stored with storage solution and if they have dried out then they need to be rehydrated in storage solution for 3 - 4 hours.
pH pens measure pH by sending an electrical current through the water. RO water has no minerals to conduct that current, so you will not get true readings.
On top of that, that little bulb on your pH pen contains some kind of solution, putting the pen in RO water can cause water to enter the bulb through osmosis. This will ruin the glass sensor.
Pens should always be stored with storage solution and if they have dried out then they need to be rehydrated in storage solution for 3 - 4 hours.