Air gap in new Ph pen electrode, normal?

[Xanode]

Picked up a new bluelab ph pen the other day, after the 24h rehydration process, the pen has been very slow to respond although eventually reads right after about 9 mins....

after turning the pen upside down a large air gap inside the glass bulb can be seen, to the point where the wire in the bulb is no longer submerged.

Anyone have this before?

 

[queequeg152]

its just an air bubble inside the reference solution.

the time it takes for an electrode to stabilize depends on a bunch of shit... as long as the calibration mV is relatively stable it should be good to go.

if the calibration mV is constantly drifting you are going to need a new electrode.

gells tend to take alot longer... liquids tend to be faster. very thin bulbs tend to be faster and thick rugged bulbs tend to be slower etc.

also if you are trying to measure something very pure like distilled water it will usually take a long time to stabilize.

in some ways... a slow electrode is more desirable as it usually means its leaching less and will probably last longer. but it can also mean its on its way out. again check the mV.