+/- 1ºC for the temperature component and 15% for the time component under isothermal conditions. The progress of the blue dye across the time-markers is calibrated to a temperature of 2ºC above the stated threshold temperature. For example, the time markers for Timestrip® PLUS 12ºC are calibrated to a temperature of 14ºC. When the product breaches its threshold temperature and is held at a constant temperature of 14ºC (i.e. isotherm), the blue liquid will reach the 1 hour print mark within 1 hour (+/- 15% in time). If the breach is at a much higher temperature than the stated threshold temperature, the indicator dye becomes thinner and will run faster.