New AC Jr user - some simple ?'s first

[johns]

Just got a AC Jr and lab grade pH probe yesterday and want to check a couple things off the bat.

First off, the Temp is reading a bit higher than my pinpoint monitor was indicating and a bit higher than I am comfortable with in general. I'd like to know if this is really the true temp. How can I tell?

When I checked the temp calibration in the Temp Setup menu, I noticed that the offset in the unit has been set to +2.5 degrees. I did not put that in there myself. So my question is, was that offset put in intentionally by you guys, or is that a mistake? The serial number of my controller is 15411, in case that helps.

Next, I ordered a backlit unit, but I dont see any light??? Is there a control for this that could have gotten turned off. Or do I need to contact the vendor I received this from to return it for the backlit version.

And lastly is there a 9V battery in this thing? How do you get at it? I didn't want to unscrew the back to look inside unless I knew for sure this was the right thing to do. And (this might sound picky but...) shouldn't I get a suction cup or something to mount the pH probe with. I really dont have any extra suction cups lying around to do this, and I bought a lab grade probe??

 

[clp]

The Jrs. are calibrated to a NIST traceable source and are +- 0.5 F out of the box.
Contact to the vendor regarding the backlight; it is always on. There is no 9V battery in the controller; the clock battery backup is done with a non user replaceable lithium battery.
We don't sell suction cups with the probes because they suck (or should a say they don't suck). Every suction cup I've used has failed within a few days to few weeks.

Curt

 

[johns]

clp- thanks

still confused about the Temp Offset value of (2.5). I assume from what your are writing above that that value was put in there for a reason, by you folks. Am I right? If so, I will leave it as is. Dont know if I could have inadvertantly changed the offset value while I was playing around with it.

And as for the backlight...that's not something I could miss right? I mean in the dark, there was no light coming from this thing at all. Had to use a flashlight to read the display. That shouldn't be the case with the backlight, right?

 

[Aquaduck]

The backlight is very visible even in a brightly lit room. Sounds like they sent the wrong one to you.

 

[johns]

aquaduck-

thanks. i'm sure it's got to be the wrong one then.

now i just need to find out for sure about that offset value in the temp calibration menu. do the units generally come with some value inserted in there corresponding to the temp probe you get? any way to check to make sure the value for my temp probe should really be 2.5?

 

[Aquaduck]

I can't say for sure. Mine was reading about 2 degrees off as well. I had two other digital thermometers that I knew were calibrated so I just changed the offset to match them. You could see if you can borrow a mercury thermometer like the ones used in school chemistry labs. Not the cheap ones at the fish store.

 

[clp]

The offset value of 2.5 sounds like the unit was calibrated by us. The backlight is very visible, and you can easily read the display in the dark if it is backlit.

Curt