Densitometer help needed

Not sure where this post belongs, but…

Are there any practical instructions out there for a Tobias TCX? I’m apprehensive to ask anything at this point as I’m not even sure how to use it. The manual is thin; web searches have turned up nothing useful so far. I have NO experience with densitometer's…and I’m sure my lack of vocabulary is not helping either.

I’m unsure if I’m zeroing it properly (I’m using the “zero” clicker switch in between readings), I get negative readings as if it’s doing math or something or maybe they’re suppose to be negative numbers...I just don’t know. I may be doing something procedurally wrong, the readings are inconsistent, even reading the calibration standard but could be user error as much as anything else. I havn't calibrated it as I don't understand how to. I really need “operational instructions” at this point I don’t even know what questions I have other than how to use it beyond turning it on, which I may be doing incorrectly as well.

Any information would be helpful...or if someone could lead me to the information I need whether its a book or website I'd appericate it.

Happy days
Mark

try Tobias

I am not familar with your piece of equipment. Try the manufacturer's web site and see if you can purchase a manual.

Mark,

I don't know your type of densitometer, but I assume its for measuring density on film.

In that case, you have to measure a density at the leading end that has no information in it. It should be blank, but normally developed and fixed. When you measure that spot, zero it on that. This means that the densitometer from now on displays the density of spots and excludes de negative-base and fog. All measurements wil be offset by the spot you used during the zeroing. In other words: all measurements are subtracted with de density at the zeroing spot.

Normally density wil be denser than the zeroing spot, and therefore display a positive value. If you see negative values, your last spot is less dense as your zeroing spot!

I hope my English is good enough for you to understand what I mean....I live in the upper part of Holland, called Friesland.

this link might point you in the right direction for a manual:

http://www.densitometers.net/support.asp

sorry, I have more experience with X-Rite and Eseco densitometers, but when you get negative readings like you describe, sometimes a densitometer can be used to average readings or they can show the difference between a series of readings etc. Sounds like you may have some of this going on....

this link is to the Tobias site though, so I bet you can get a manual from them--if it was an X-Rite model, most of their manuals are online even for the stuff they don;t make anymore. Could be Tobias is the same way. Good luck and hope this helps.

I've been to their site and like I said I do have the manual which does tell how to use it...sorta.

emusief, thanks a ton, the (-) makes a little more sense now and was exactly the kind of answer I needed, and I'm sure I'll have more.

Happy days
Mark

thanks for the link DKT, I should have mentioned that this seems to be quite old and was unable to find anything about this model (TCX) on their site.

I am really in need of the Densitometer for dummies instructions...thanks everyone.

Happy days
Mark

I visited the new guy from Brooklyn, Saganich's site>technical>Zone system>densitometer. Granted it is not info on "your" unit, but it is a straight shot at a use of one.