Is there standard way I should calibrate a new pen?

[mrmors]

I've tried doing a search for 'calibrate' and 'calibration' but not having much joy.

I've been using standard insulin syringes for months and months, but though I'd give a gensupen2 a try for one of my daily doses.

I put in blank cartridge full of tap water, primed the air out etc with a needle tip, then took the tip off. I then did the following tests:

-Attached/injected the cartridge with a 1ml, 31gauge syringe, and tried to backwards inject it with 10units x2

-Attached/injected the cartridge with a 3ml, 27gauge syringe, and tried to backwards inject it with 10units x2

-Put the 31gauge micro tip needle back on to it, and injected 10 units into the an empty 1ml syringe with the plunger pulled out x2

-Put the 31gauge micro tip needle back on to it, and injected 10 units into the an empty 3ml syringe with the plunger pulled out x2

I don't know really any other way to test it.

BUT, I got 4 different results from the 4 different tests I ran, none of them giving me 0.1ml of water on the other side. All tests were 10-20%, but they were consistently 10-20 out. e.g the test into the 3ml syringe was giving me about 90% accuracy, on both attempts, bang on. Same for the 1ml syringe, giving me 80% bang on.

So I've no real idea what I should dial the gauge to for a standard dose. I've been winging it and setting it to 24, to to try and get a 20unit dose, as that seems to be sort of in the right ball park from my testing.

It seems, the dial accuracy, to actual delivery accuracy is closer, IF you use a larger gauge needle like the 27 of lower, seems the pen struggles to deliver accurately if you use super fine needles.

How do you regular pen users do it? Am I missing an easy trick to calibrate?

 

[bbbilly]

ive seen several videos from the peptide critic on youtube where he loads up the pen then puts a normal easy touch syringe in the end and does like 10 units to see if the syringe fills up to the 10 unit mark. then just use that syringe before you switch fully to the pen

edit for clarification.

he just sticks the syringe into the rubber stopper of the cart like you would when filling it. then injects the test units through the needle into the body, without removing the plunger. it just gets pushed back when you push the pen plunger. if its off, well idk what you could do other than just know what the delta is. if its 5 units short at every unit test then you know its just 5 under and need to note that. if its not atleast consistent with how far its off or if it increases or decreases based on how many units you push then i wouldn't even use it. to the best of my knowledge you cant adjust them, if they are off then you are stuck with it.

 

[eidos]

Your four methods are all valid; their practicality and accuracy vary depending on the size of the syringe, but they shouldn’t produce such different results. Do you get consistent results when you use the same method multiple times?

I've given up on the v2 pens, the ones with the flat, retractable top. I have some v1, v3, ergo2, and my favorite, the Gansulin, which are all precise and consistent. Above all, they apply the right amount of force to the piston without skipping a click.

Sometimes there's a problem with the vials: the moving seal that acts as a piston is upside down. Take a look at an insulin syringe: you'll see that the thick part is on the shaft and the thin part is on the side of the liquid. It should be the same inside the pen's cartridge.

 

[Pocket]

When you are backwards injecting the syringes, are you using fresh syringes? Or are you flushing them with water first? Cause if there is air in the needle, that can compress and throw off the reading. If you flush the syringe first where there is leftover water in the needle, it should give you a more accurate reading of the dosage from the pen. Not sure if this is your problem, but want to help rule it out.

 

[mrmors]

@bbbilly mine is off, but consistently off, and I've currently accepted a delta of 4 for a 20 unit dose, so I use 24 instead. This seems to give me nearest to 20 units in a 1ml syringe as an average between reverse injection, and injecting into a syringe with no plunger.

@eidos I do get consistent results when repeating the various methods several times. But I've ended up staying with the results from using the 31 gauge tips, as that would be my delivery method.

@Pocket I was using fresh syringes for each test, to start with, but didn't really record the first result as I thought it might skew the results the plunger doesn't go all the way to the end of the chamber, so I thought I'd do a few tests after the water had been in the first time, and the results were pretty much the same every time. lower the gauge, the more accurate the delivery, but I'd be using high gauge needles.

 

[Pocket]

@Pocket I was using fresh syringes for each test, to start with, but didn't really record the first result as I thought it might skew the results the plunger doesn't go all the way to the end of the chamber, so I thought I'd do a few tests after the water had been in the first time, and the results were pretty much the same every time. lower the gauge, the more accurate the delivery, but I'd be using high gauge needles.

Ahh. Gotcha. Well I'm glad you ruled that possibility out. Sorry your pen isn't measuring correctly though.

 

[eidos]

@bbbilly mine is off, but consistently off, and I've currently accepted a delta of 4 for a 20 unit dose, so I use 24 instead. This seems to give me nearest to 20 units in a 1ml syringe as an average between reverse injection, and injecting into a syringe with no plunger.

@eidos I do get consistent results when repeating the various methods several times. But I've ended up staying with the results from using the 31 gauge tips, as that would be my delivery method.

@Pocket I was using fresh syringes for each test, to start with, but didn't really record the first result as I thought it might skew the results the plunger doesn't go all the way to the end of the chamber, so I thought I'd do a few tests after the water had been in the first time, and the results were pretty much the same every time. lower the gauge, the more accurate the delivery, but I'd be using high gauge needles.

The most important thing is consistency. This allows you to determine if there is a systematic error, and you can adjust your concentration or the number of clicks based on this.