An apparatus and method for measuring, collecting, and processing the temperatures of a number of hot junctions in a thermocouple sensor array simultaneously comprises means for measuring the temperature of one or more reference junctions and means for collecting, processing, storing, and transmitting data collected from an array of thermocouple temperature sensors. The valve is constructed with an elongate stem or shaft that facilities the assembly of the valve into the trigger sprayer and a positioning plug that solely holds the valve in a centered position in the liquid passage of the trigger sprayer. Received orders are matched against orders in the order book in accordance with a FIFO andor workup protocol, as a function of preferences selected by the traders andor the system operator.