Hi
@Dernspiker and welcome to the DCUK forums.
I use a dexcom G7 with a tandem tslim pump (previously using a G6).
I second
@Jaylee 's calibration suggestions to only calibrate when the graph is showing a straight line.
I have had quite a few chats with dexcom customer support about calibration and they told me not to calibrate in the first 24 hours, because your body's reaction to the sensor means that it can be quite inaccurate for the first 24 hours and if you calibrate too early then it'll read incorrectly when you've finished the reaction. I try to preinsert my new sensor by about 12 hours to get round this issue. (I insert a new sensor at the start of the 12 hour grace period from the old sensor , but don't activate it on my pump till the end of that period.)
If the sensor reading is wildly out, dexcom won't let you do the calibration. (This is usually the point at which I reckon I have a bad sensor and contact dexcom for a new one.)
And I definitely do a bg test if I don't trust the reading on my dexcom. Glucometers can be inaccurate too, but if your hands are clean then they should be more accurate than a sensor. And I find glucometers
much more accurate during hypos. That is the main time I use mine, because the dexcom reading lags and will tell me I'm still going down when in fact my bg has started to rise.
But dexcom customer support also told me not to calibrate "too often". I basically got the impression that they would prefer you didn't calibrate the G7 at all...
Now I know not to believe the sensor for the first 12 -24 hours I get on much better with it. Though occasionally I do get a bad batch of sensors, they seem to have become more reliable over the last year.
