PH Pen - Forgot how to Calibrate

[Loopy]

EDIT: FORGOT. For some reason the word Forgot did not show up on the subject

I forgot how to calibrate my PH Pen. I lost the box that it came with. More like I forgot where it is.

I bought it from Polyart C328 Singapore. I could give them a call but I don't speak Mandarin and chances are I will not be able to articulate my needs.

Though if I can't get the answer I will go down tomorrow and just bring the pen down; not before I check here.

It say PH Test on the Pen and there are 2 screws, on outside and one inside.

I cannot remember which screw is for which buffer solution! The one outside and the one inside.

The pen is rectangular'ish and is blue. It is just written PH Test on the pen. Looks like a marker.

Any of you have any idea?

Thank you,
Best,
Loopy

[Loopy]

Ok I got the answer to this. The 7.0 Buffer grub screw is on the outside, the 4.0 grub screw is on the inside

[tawauboy]

glad that you found the answer already.
dipping it into a known buffer solution and tuning either screw will tell you the answer rather quickly.

[Loopy]

Thanks I called up the LFS and asked them about it. It was negatively .20 off. Thankfully I saw to it. Because I have been wrestling with my perimeters the past 3 days.

glad that you found the answer already.
dipping it into a known buffer solution and tuning either screw will tell you the answer rather quickly.