? Caliper Calibration

Hello all,

I am looking for some help. My calipers arrived today, yay! I dont think my exact syringes are listed in the instructions on the sticky. A pic of my syringes is attached.

We have calculated that 1iu has an average of 2.38mm, averaged across 9 syringes. My worry is that all the syringes listed in the sticky, are between 1.2 and 1.6mm so mine seems much higher.

Can anyone help please!

 

@nslade001

@Sandra And Buddy

@Sue and Luci

@MrWorfMen's Mom

@Wendy&Neko

 

I'm going to tag @Marje and Gracie - she wrote the book on calipers and may be able to offer the best advice on calibrating your calipers. You may want to post a pic of your calipers AND your syringe - out of the wrapper - so she can see them 'in person'...

 

@Marje and Gracie Is the one to help with this, I believe she has a chart for those ones.

 

Thanks Sue, I didnt realise Marje had written it. Feel so blessed to have you all xx

 

This is where I am up to

 

Very nice! Although I think you may need to move the calipers down a tad to just underneath that little lip thing. Marje may have those syringes - I don't...so don't take my word on it...I hope she'll be along soon.

 

Those look like my syringes (same brand BD) and they are a nightmare to measure because of a protruding lip around the top of the barrel. As long as the measure is always done from the same point on the syringe, it's fine. Wendy and I used the same syringes but didn't come up with the same measures....close but not the same. I dug out my old measure of my BDs and I came up with 1.62 for 1u measuring roughly the way you have.
Measure down to 5u and then divide by 5 for one unit and see what you get.

 

I also think you are measuring a bit too high and that’s why you are coming up with a larger number. You can also measure between units, say between 1u and 2u or 2u and 3u. You might want to experiment and be sure you get the same number. But, ultimately, it’s going to be a question of how you can easily, consistently dose so if resting the upper arm like you have it can be done consistently, then it doesn’t really matter what the distance in mm is that you determined.

I do know that @Wendy&Neko used the smaller arms for her BDs. Have you tried that? I’m tagging her so she can offer some suggestions as to how to do that as I never needed to with my syringes and it would have been difficult to do so.

 

Thank you all so much.

So we have remeasured and redone the average from the new point below the lip. Our average is now 1.5316mm, so this seems more in line.

Just about to test between the other numbers to gauge some consistency.

So grateful the husband is the engineering/mathematical type...

 

I am going to copy and paste a couple of posts I wrote with pics I took. The calipers here are set to 1.3Units, not 1.0 Unit. It shows where to set the edge of your calipers:

Hi, so these aren't great pics but I did my best! I found a syringe that *almost* lined up where the zero line is (assume it does). You use the small side of the calipers use the space between the overlap...This avoids that protruding ridge on BD syringes. Line the top to the inner plastic ridge line (the shaded bit) and draw insulin to the bottom edge of the calipers...Mine are set to 1.3U but it's a bit difficult to tell because I couldn't hold them both and the camera too lol.
If you want I'll try to take better pics when hubby's home.
i

Here's the second post, showing a mismarked syringe:

Lol I was poking thru the sharps container for a mismarked syringe...Not hard to find. Here's one where the zero obvs doesn't line up with the inner line:
And this is where you'd hold the calipers (again, not 100%accurate lol)
See how it looks like I'm only giving around 1U, because of the mismarking? If this syringe's lines were used and someone drew what they thought was 1.3U, they'd be giving more like 1.6ishU, because the zero line is too low.


I hope this helps.
With my measurements, 1 U = 1.5mm

It is very important to measure from the inside ridge as shown. If you measure from the outer lip as you are, you end up with a much larger amount of insulin given as a "unit", even though you're being consistent.

With love, Nikki

Editied to add these pics are using the small sides of the calipers.

 

Hi all, thank you thank you thank you.

So we have redone all our measurements and I'm happy that the 1.53mm =1iu. So therefore my 1.5iu dose = 2.29mm.

However, on the syringe this is a fat 1iu, so a lot less than I've been giving.

I have just done my PMPS and he is "hi".

I really think I need to go to a caliper 1.75iu. Do you agree? I've tested quite a bit today and he hasn't gone that low at all.

Need to shoot ap any help appreciated. To add, negative ketones today

 

@Marje and Gracie I hope you dont mind me tagging you, you're the only one i can see online and i need to shoot. Thank you and apologies for the directness x

 

Had to shoot, went with a caliper 1.75iu which was a fat 1.25iu on the syringe. I will go with the calipers from here on in for consistency.

 

I’m sorry...I wasn’t on long as I have company coming and just checked back in really quick.

Good luck with the calipers!!

 

I did not find the BDs to be a nightmare at all for using calipers. And my measurement per a unit was 1.5 units, pretty much the same as you. But like Marje said, I did not use the big arms for measuring, I used the little pair of arms across from the big ones. The big ones are used for measuring the outside diameter of things, the little ones for the inside diameter, and made it easy to get inside the BD lip. But they still measure the same amount.

For your first dose using calipers, drawing insulin the old way, then measuring is fine. Just be aware, as Nikki’s pictures showed, often the BD’s zero line is in the wrong place. The last bags of syringes I used, Neko’s dose was under the zero line. There was still insulin in the syringe there, occasionally over 1/3 of a unit. What I did was first push the plunger up to the top, and see where the real zero line was, then measure from that.

Keep an eye on Toby tonight, some kitties go higher before diving down.

 

What I would do would be to measure the distance for 30 units and divide that by 30 to determine the distance for 1 unit. Then for dosing measure/determine the distance from the plunger full depressed to the dose you want.

 

Thank you all, I am using the small side, as you say you can get under the lip with the inside of the calipers. I am already noticing such a variance in the syringes, trying to ignore the lines and just go with the calipers from here on in.

Thank you all for your help and advice, I am pleased I am using them, consistency is key and it seems Toby is very sensitive so this is even more important.