T1D glossary

Sensor warm-up

Also called warmup, warm-up period.

Sensor warm-up is the wait after a new CGM sensor goes in, before it shows glucose values and alerts. The length depends on the model: 30 minutes for the Dexcom G7, 60 minutes for the Dexcom G7 15 Day and the FreeStyle Libre 3. (Dexcom; Dexcom; Abbott; NIDDK (NIH))

Worked example

A Dexcom G7 inserted at 7:00 p.m. starts showing values at about 7:30 p.m. A FreeStyle Libre 3 started at the same time shows its first value at about 8:00 p.m.

Related terms

• Continuous glucose monitor
• Signal loss
• MARD

Sources, quoted

• Dexcom: “30-minute sensor warmup”
• Dexcom: “Dexcom G7 15 Day uses a new algorithm that allows for 5 additional days of wear, currently requiring a 60-minute warm-up.”
• Abbott: “60-minute warm-up required when starting the sensor.”
• NIDDK (NIH): “how long it takes the CGM to warm up”

Every quote above is checked against its source page before each update of this site; last checked 2026-10-06. The worked example is our own arithmetic. This page explains a term; it is not advice for a person's treatment.