TaylorPrecision Products Folding Stem Digital Display Food Thermometer, One Size, Black

Is this considered an instant (a few seconds) thermometer - that is my primary need.

Can I use this to check temp of oil when deep frying?

How do you calibrate this thermometer it keeps reading -40°F after changing the battery.

What are the actual dimensions of this...the pic says 4.5, 2.75 for the probe and 1.75 for the body? the pic shows the body as bigger?