You calibration standards are what usually dictate this frequency. However, I would still continue to have the calibration done annually, if nothing more than peace of mind that the results were as accurate as possible. Especially for Engineering R&D.
You calibration standards are what usually dictate this frequency. However, I would still continue to have the calibration done annually, if nothing more than peace of mind that the results were as accurate as possible. Especially for Engineering R&D.
I'm going to use the words calibration standard in a different capacity. Do you have a calibration standard that came with your arm? It's a bar with some holes that look like they were made with a center drill on it, and lengths identified on it for the pitch between those holes. If you do, and you're looking to save a few bucks, send the bar out for calibration yearly, and the Romer out every other year. The bar is a lot cheaper to certify ($50-100 versus $2000), and you can use it in house along with the cimcore software to verify that length and point checks are still giving good numbers. If you've never done the length or point checks, PM me and I'll give you a more detailed explanation of what to do and what you're looking to see in terms of variation and error.
We do as KamikazeKonrad has mentioned. We calibrate our calibration standard bar on another CMM, and check the ROMER calibration to that. When we first got our ROMER, we had to send it out to get the entire arm calibrated. Something about the readers were out of whack, and it would not repeat. You should not have to send the entire arm out as long as it calibrates good to your calibration bar.
I do check the arm with the bar about once a month, this is one of the reasons I was questioning sending it out for calibration. When times are tough its hard to justify spending that much money for calibration when the arm is working great.
I like the idea of calibrating the bar yearly and the arm on alternate years.
If you wouldn't mind telling me...where do you get your bar calibrated? The company we purchased our arm from recently quoted me $300 to calibrate the bar. That seems a bit excessive...
I'm going to use the words calibration standard in a different capacity. Do you have a calibration standard that came with your arm? It's a bar with some holes that look like they were made with a center drill on it, and lengths identified on it for the pitch between those holes. If you do, and you're looking to save a few bucks, send the bar out for calibration yearly, and the Romer out every other year. The bar is a lot cheaper to certify ($50-100 versus $2000), and you can use it in house along with the cimcore software to verify that length and point checks are still giving good numbers. If you've never done the length or point checks, PM me and I'll give you a more detailed explanation of what to do and what you're looking to see in terms of variation and error.
Just look at an accredited lab that does 3rd party calibrations or inspections. They will inspect and certify the bar. Honestly though $300 isnt that out of line considering it is alot cheaper then the $1500-$2500 it costs to calibrate the arm along with the downtime in not having the arm available.
I also know that some people will buy additional bars and just have them due at opposite years so that they always have a standard.
We do as KamikazeKonrad has mentioned. We calibrate our calibration standard bar on another CMM, and check the ROMER calibration to that. When we first got our ROMER, we had to send it out to get the entire arm calibrated. Something about the readers were out of whack, and it would not repeat. You should not have to send the entire arm out as long as it checksgood to your calibration bar.
Colin, what is wrong with Chally72's statement? I mean that is the purpose of the bar is it not? It is to be used as a standard to make sure that the arm is checking within the stated/calibrated spec, and I would do as Kamikaze suggests with sending the bar out for recertification by a third party. I would also suggest to anyone to take screenshots of your single point checkouts and the length checkouts and keep a internal log in case there is ever a issue with a customer or internally so you can show with documentation that your arm has been in spec and curb the constant blame on the cmm equipment. These checks only take a few minutes as you get more comfortable with the system and the daily log take away any questions and clears up any concerns on if the system has been messed with.
