What is the accuracy of the hour marks?

Every Timestrip® PLUS product is calibrated to a temperature of 2˚C above its stated threshold temperature. For example, Timestrip® PLUS 12˚C is calibrated to a temperature of 14˚C. When the product breaches its threshold temperature and is held at a constant temperature(i.e. isotherm) of 14˚ C, it will reach the 1 Hour print mark within 1 Hr (+/- 15% in time).

adminWhat is the accuracy of the hour marks?