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I am new to diabetes testing and currently am only testing 3 times per week as a precaution due to a reading of 128 on a blood test by my doctor. I have a One Touch Ultra 2 meter. Here is what has me baffled. Last night after receiving my meter last night I tested 3 times in the space of 5 minutes on different fingers and hands and got 3 different readings 124, 114, and 134. This morning after fasting overnight I got a reading of 101, and 128. How do I know which is right and which to record? Is this normal?
 

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It is very important that you wash your hands with soap and water before testing. Even the tiniest bit of material from the previous time you ate can affect a test result. Meters do vary, all of them do. There are many references I have seen that suggest there is as much as a 20% variation between results when doing multiple tests like you have mentioned. I know people who claim that some meters vary less than others. I use the Free Style meter and it verys very little but I can get a 95 and a 106 on consecutive tests. That is to be expected. I know it is frustrating but we have to live with it. Your meter is a very popular brand and I do not think it is necessary to buy a different brand.

Richard
 

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several options

does it need to be calibrated?

There is a range of 5%-10% in result accuracy.

Did you make sure your hands were clean?

Iris peleg
 

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does it need to be calibrated?

There is a range of 5%-10% in result accuracy.

Did you make sure your hands were clean?

Iris peleg
A meter cannot be calibrated. You can use the control fluid to verify that the strips are within range, but there is nothing anyone can do to change the accuracy of the meter. What is most necessary is what you and Richard already said. Understand the range of accuracy, and be sure to wash your hands with soap and water every time. Handle the strips carefully, keep them and the meter in the same place so the environment, temps and humidity, are the same, and try to remember that the meter doesn't change accuracy. The differences you may find, will come from the strips, your skin, and even from your own blood.

Most "newcomers" need a while to get used to these factoids, but its best to just test once, and call it good. Then do the same thing over and over being consistent as possible. Use your meter to record trends, not to determine your exact BG levels. That cannot be done with any device. Even the lab equipment can and does vary within 10%-20%

P.S. A BG reading of 128 doesn't indicate anything. If you doctor took just that one reading, and thinks you may be diabetic and so he told you to test any old time, three times a week, find another doctor. If there is suspicion of diabetes, you need to be tested. Now. Random readings don't mean a darn thing. If I took random readings, I would not end up looking like a diabetic. That is not how its done, and its time for you to find out the truth, even if its not something you want to really know.

You need an A1c test, possibly followed by a fasting glucose tolerance test. You can buy the A1c test at many pharmacies, and do it yourself if your doctor seems unwilling.

If you have doubts, eat a nice big meal with a large helping of potatoes, or have a big old bowl of ice cream and/or a good slice of cake or brownies. Wait about an hour, then test. That number will tell you a lot about where you are headed.

Random testing? Waste of good money.

John
 

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A meter cannot be calibrated. You can use the control fluid to verify that the strips are within range

John
There are glucometers that have code on each strip box or has special calibration stick in each box. The one with the spacial code like old freestyle has to be calibrated with the specific code so that when a strip is stuck into it it shows the correct code. The one with the special stick have special slot to enter the calibration stick to.

Iris peleg
 

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There are glucometers that have code on each strip box or has special calibration stick in each box. The one with the spacial code like old freestyle has to be calibrated with the specific code so that when a strip is stuck into it it shows the correct code. The one with the special stick have special slot to enter the calibration stick to.

Iris peleg
But this does not calibrate the meter. The meter remains unchanged. What changes is the firmware inside the meter adapts to the different kind of strips that come in each lot via data given by the code, since the strips change from lot to lot.

The meter cannot be changed from the factory. All the code setting does is tell the meter what to expect. It doesn't change anything in the meter itself.

Calibrating the meter implies that you are altering it, to compensate for its own inaccuracy, and that cannot be done to the meter. It can compensate for the inaccuracy in the strips, from lot to lot, but if your meter reads 10 points low, it will always read ten points low, no matter what you do with it. The variable is the strips, so the manufactures allow for the meter to adapt to the differences in the strips due to manufacturing standards.

The accuracy of the meter is fixed. If your meter is off by X points, there is nothing anyone can do to change that. Even after the control fluid test, the meter will still be off by 10 points

John
 

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Glucometers / Glucose Meters - American Diabetes Services

I guess that you are hardware or software engineer but there are all kinds of calibrations. There are strip calibration as you can see in the ref link. Ty to google calibration glucometers
There is nothing you can do to change the calibration of your meter to make it read more accurately. You can tell it what kind of strips it can expect to see, but that is all you can do. If your meter is inherently inaccurate, which many are, it will continue to be inaccurate no matter what you try to do with it.

Calibration implies being able to change the accuracy of the meter, and you cannot do that. You can change the tint and the color on your TV by adjusting certain knobs, you can even raise and lower the volume with one button. Nothing you can do,will change the accuracy and precision of a home glucose meter.

Do you think that using control fluid tells your meter to adjust itself accordingly? If meters could be calibrated to be 100% accurate, can you explain why everyone on this and every other board has issues with the accuracy of their meters? :)

Its because they are calibrated at the factory through design specs, and there is nothing the user can do to alter that.

Now, we could be playing with semantics here, L-) as you idea of calibration may be different than mine. To me, calibration is when you find out that your meter is inaccurate, and you make and adjustment that will cause it to become accurate. Can you do that with your meter? Can you adjust your meter until it is 100% dead on accurate through any 'calibration' method? I don't think you can, so perhaps our expectations are just different in the definition of the term?

The control fluid test only lets you know if your strips are okay to use. The Code system simply tells the meter what 'batch' of strips it should expect to see. Some meters read the code that is embedded in the strip, and automatically adjust for it. Others, like the Ultra Mini, require the user to set the code for each batch of strips. Neither of these make the meter more accurate, they only tell the meter information about the strip that it is going to be reading, and what to expect from the sample. The problem with getting consistent readings is found in the manufacturing process of the strips, not the meters.

If your meter is coded properly, your control fluid test is within the specified range, and your meter is off by 10 points, you meter is off by ten points and there is nothing you can do to change that.

John
 
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