Support

• Why does the app want me to pre-chill the box for an hour first?

  A room-temperature cooler spends its first ice on cooling its own walls. For an 8 kg box that is roughly 720 g of extra melt — on top of maybe 97 g of genuine hourly melt, which would throw the result off by several times. The hour of pre-chilling, with that water poured away, gets the walls out of the measurement.

• Why does the run have to be three hours or longer?

  Weighing error stays the same size no matter how long you wait, so a short run magnifies it. At one hour, a ±20 g slip spreads the prediction across 1.8 to 2.7 days. At three hours the same slip narrows it to about 0.15 days, which is why three hours is the practical floor.

• Can I test with gel packs instead of ice?

  No, and the app will say so rather than produce a figure. The method depends on the contents sitting at exactly 0°C while they thaw. Gel packs are formulated to change phase at a different temperature, so the heat bookkeeping no longer holds. Plain water ice only.

• Do I need a thermometer?

  No. A kitchen scale is enough, or a measuring cup if you would rather read volume. You do need the outside air temperature, which you can type in or let the app fetch for your area.

• Does this tell me whether my food is still safe?

  No. ChillTest answers one question — how long ice lasts in your cooler — and nothing about food safety. It is not a food-safety device, it does not know what is inside the box or how warm it got, and it makes no claim about whether anything is fit to eat. Follow proper food handling guidance for that.