Climate and food

Temperature is the one thing in a van that goes wrong slowly and silently. Three instincts watch it, and they all work the same way: you tell Sensa which thermometers matter, and the instincts take it from there.

Choosing what is watched

A van can carry several thermometers, cabin, outside, fridge and freezer, and nothing in the readings says which is which. So every device that reports a temperature carries three switches of its own, on its row on the Devices tab of Settings:

• Fridge, for a probe living in the fridge.
• Freezer, for a probe living in the freezer.
• Temperature Watch, for any thermometer you want told about sudden changes.

All three are off to begin with. Switch on the ones that apply to that device, and the matching instinct starts watching it. You can flag as many devices as you like, and one probe can carry more than one flag: a fridge probe with both Fridge and Temperature Watch on is watched for running warm and for changing fast. Until at least one device is flagged, the instinct appears in the list but does nothing.

Thresholds are set in °C and converted to whatever unit your thermometer reports, so a probe reading in °F still works correctly.

Fridge watch

A door left ajar, or a fridge quietly giving up. Sensa watches every device flagged Fridge and speaks up when one stays above your threshold for fifteen minutes. The delay is there so that unloading the shopping does not set it off. Each fridge is watched on its own, and the alarm names the one that is warm.

Settings: Alert above 8°C, range 2 to 15. One threshold covers every flagged fridge.

Default: Alert.

You need: a temperature sensor inside the fridge, such as a RuuviTag or a Govee probe, with its Fridge switch on.

Freezer watch

The same watch for the freezer, with a threshold to suit. Sensa watches every device flagged Freezer and speaks up when one stays above your threshold for fifteen minutes.

Settings: Alert above -12°C, range -25 to 0. One threshold covers every flagged freezer.

Default: Alert.

You need: a temperature sensor inside the freezer, with its Freezer switch on.

Temperature watch

A watch for speed rather than level. It speaks up when any flagged thermometer rises or falls by more than your chosen amount within your chosen time, whichever direction it moves. A fast change usually means a door left open, a power loss, or a heater or cooler running, and catching it early is what stops food spoiling or a cabin overheating.

The alarm names the thermometer and says whether it is rising or falling. It never fires at start-up, because it needs a little history before it can tell how fast anything is moving.

Settings: Change of 3°C, range 1 to 20 in steps of 0.5. Within 30 minutes, range 5 to 240.

Default: Alert.

You need: any temperature sensor with its Temperature Watch switch on.