How does calibration work when using two monitors with either the G4 or the G5?

Continuing the discussion from Time for a new pump. Looking for opinions:

[quote=“Thas, post:5, topic:48654”]
I have seen very few times when the Vibe’s CGM and the Dexcom receiver have been different by more than 5 points[/quote]

Since I do not use the Dexcom CGM I don’t have first hand experience with it. One of the things I have wondered about is how calibration works when someone is using either two separate monitors/receivers or is using a pump which can function as a monitor such as the Vibe together with a Dexcom monitor.

Do you have to repeat the calibrations on both device? In other words, do you test your BG with a meter and need to enter the BG value as a calibration on both devices to ensure they are both working from the same set of assumptions?

The engine that gets calibrated is in the transmitter, not in the display device.

Good to know! I kinda suspected this because it makes a lot of sense.

I use an iPad with G5 app and the Dexcom receiver. If I calibrate with one, it will update to the other (vice versa). Note: this is not the case when using the FOLLOW app.

With the G4, the calibrations have to be entered on both receivers - But I can use the same BG test. Sometimes, I have the two receivers on different schedules and on those occasions I’ve used the reading on one receiver for one of the two startup calibrations on the other – assuming it was reasonably well in-line at the time.

Not sure if this exactly fits what you’re asking, but with the G5 you can enter the calibration value in either your receiver or your iPhone and the other one “knows” it’s been done. But @Helmut is right, it’s the transmitter that is actually being calibrated.