Hamilton Syringe Question

[Marcaine17]

Hello,

I have a question regarding the Hamilton 701SNR 10ul Syringe (22s/2''/3) model number 80365 ( http://www.hamiltoncompany.com/item/view/c/110/p/1454/ )

A few months ago, we borrowed these syringes along with a pump for a neighboring lab to use for cannula injections. In order to properly calibrate the pump, you need to enter the inner diameter of the syringe barrel. Harvard requests the inner needle diameter, however, Hamilton lists this information as the inner barrel diameter. It makes sense that what Harvard really wants is the barrel diameter, as this is what the needle plunger is moving through to expel the fluid. After some confusion, we realized that the inner barrel diameter of these needles is .46mm, which is the number this lab had been using for ~8 years. So everything made sense.

Today, we revisited the website, as we were using the same syringes with a different model pump. However, when we checked the website to verify it was indeed .46mm, we now find it listed as .485mm. We called Hamilton and they claimed nothing has changed, however we have a series of e-mails documenting our confusion, which provides the exact link above stating the inner barrel diameter is .46mm.

We are looking for help of anyone who has used these needles before. Do you have a hard copy of the data sheet for this needle? The only possible explanation we can come up with is that Hamilton has changed their information, without making it known. If this is true, it would mean that people have been reporting different injection volumes then what they actually used.

If anyone has information regarding these syringes and the barrel diameter they have used, please let me know. We're very curious to find if we (as well as our neighboring lab) have been wrong for years, or if Hamilton has recently changed their information.

Thank you!

[Nathaniel Ryckman]

I tried scouring the internet for the barrel diameter of the syringe that you are using. The idea is that if the website had previously used 0.46mm for displayed measurement, then perhaps there would have been another website with an outdated or cached value that would still be displaying 0.46mm. Instead, I only found other websites with the 0.485mm measurement. Obviously this isn't definitive proof, but I thought that, if you wanted, you could try to contact some of these other websites to see if they by chance noticed any changes.

Probably one of the best companies to call since they seem to either provide Hamilton with the syringes or compete with Hamilton by offering replacement syringes:
http://www.labicom.cz/clanky_img/SGE%20Syringes.pdf

I am giving the reference to this website since they list the measurement under a slightly different title and make a note about the model of syringe that you are using. I don't know if it's significant or not, but I thought I would offer just in case:
http://www.hamiltoncompany.com/Syringes/techInfo/syringeDimensions.php

This website looks interesting because the PDF that they supply looks like it's in a possibly older format. Perhaps this is an indication that the measurements have been around for a while? Perhaps, you could contact the website to find out how old the PDF is:
http://www.amchro.com/PDFs/Spritzen/syringe-dimensions.pdf

I think these websites probably just pull data automatically from the Hamilton website, but, again, this might be another possible lead:
http://www.analytics-shop.com/de/angebote/701-n-10-l-spritze-26s-51-2.html
http://chromatography-online.co.uk/catalog/hamilton-701npt5-10ul-syringe-26s25-80339-p-844.html

Anyway, good luck! Sorry I couldn't help you better.