Support

• Why do I have to pre-chill the cooler for an hour first?

  A cooler at room temperature spends its first ice cooling its own walls. On an 8 kg cooler that is roughly 720 g of extra melt, against maybe 97 g of genuine melt in an hour — enough to skew the result several times over. The hour of pre-chilling, with that water poured off, keeps the walls out of the calculation.

• Why does the run need to be at least three hours?

  Weighing error does not shrink as time passes, so a short run magnifies it. Over one hour, a ±20 g slip scatters the prediction from 1.8 to 2.7 days. Over three hours the same slip narrows it to about 0.15 days, which is why three hours is the practical minimum.

• Can I test with ice packs instead of ice?

  No, and the app will tell you 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 breaks down. 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 — type it in, or let the app fetch it for your area.

• Does it 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 or how warm it got, and it makes no claim about whether anything is fit to eat. Follow proper food handling guidance for that.