measuring, calculating, monitoring, electrical control, scientific, electrical, electronic and optical apparatus and instruments all used in the production storage, handling, monitoring and preparation of food, namely infrared thermometers; digital thermanemometers; hand-held digital thermometers; pocket electronic thermometers; temperature loggers, namely heat monitors with an attached display screen which displays the temperatures logged, and/or with attached computer printers for printing the different temperatures tracked by the instrument; computer printers for generating printouts of temperatures, humidify and pH levels; water meters, namely digital meters for measuring pH levels in liquids; gas meters, namely digital meters for measuring temperature, humidity and pH levels in gases; digital tachometers; AC and/or DC powered gas meters for measuring humidity levels and temperature in gases; portable combustion analyzers, namely gas meters for analyzing gas composition, monitoring emissions, measuring gas temperature levels, and analyzing combustion efficiency of boilers, and/or with attached gas pressure sensor and/or with attached computer printer for printing the different information analyzed by the instrument