Electrophysics CT-33

[davidpm]

I have the above unit an when I I check it with the copper plate and plexi test panel it reads 15 instead of 14.
There are 3 screws on it non of them seem to change the needle down.
The center one will make it go up if I move it either way.

How do I fix this?
Does it matter much?
Anything under 15 is dry anyway and anything over 20 something is wet and the middle is the middle.

[amarinesurveyor]

David, I have the same meter and have been using it for at least 7 years, maybe more. When calibrating it, the copper plate goes on the bottom with the copper facing up, then the plexiglas goes on top of that. First set the zero adjust screw to zero the meter, which is under the left white plastic removable plug. Then remove white plastic removeable plug and place the meter on top of the plexiglas. Adjust the meter to read 14%, then repeat the process (adjust to zero and then adjust to 14 %) until they both remain constant. You need a very small straight blade screwdriver to do this. Hope that is clear.
Brian

[eherlihy]

Also have that meter. What appear to be nylon phillips head screws are actually covers for the (slotted) adjustment screws. Remove them to access the adjustment

[davidpm]

Originally Posted by amarinesurveyor

David, I have the same meter and have been using it for at least 7 years, maybe more. When calibrating it, the copper plate goes on the bottom with the copper facing up, then the plexiglas goes on top of that. First set the zero adjust screw to zero the meter, which is under the left white plastic removable plug. Then remove white plastic removeable plug and place the meter on top of the plexiglas. Adjust the meter to read 14%, then repeat the process (adjust to zero and then adjust to 14 %) until they both remain constant. You need a very small straight blade screwdriver to do this. Hope that is clear.
Brian

This site says copper down
Understanding the Moisture Meter / Electrophysics CT-33 Photo Gallery by Compass Marine at pbase.com

I tried it both ways and copper down reads 14 and copper up reads 15 both with the plexi spacer
In practice it probably dosn't matter much.
I use 0 to 15 for dry
15 to 23 for somewhat wet
23 to 30 really wet

So one percent isn't going to change the diagnosis significantly.

[davidpm]

Originally Posted by eherlihy

Also have that meter. What appear to be nylon phillips head screws are actually covers for the (slotted) adjustment screws. Remove them to access the adjustment

So I've been adjusting the covers all this time.
Thanks works good now.

[Maine Sail]

Originally Posted by davidpm

So I've been adjusting the covers all this time.
Thanks works good now.

Yep... Should adjust fine now...

[eherlihy]

Originally Posted by davidpm

So I've been adjusting the covers all this time.

Words fail me...