Volume air flow sensors based on NTC thick film segmented thermistors

Purpose - The aim of this paper is to investigate the behavior of a new nanometric particle NTC thermistor paste and thick films obtained by screen printing. Design/methodology/approach - Nanometric powder of NTC thermistors based on complex spinel was made by calcination of an oxide mixture and ultra fast ball milling. Characterization of the new powder was done on compacts sintered in different conditions. Segmented thermistors were screen printed on alumina substrata, dried and fired in a conveyor furnace at 850 degrees C/10 min. Segmented thermistors were indirectly heated by a glass sealed heater placed between them in the middle. The system was put in a tube with a regulated air flow to serve as a volume thermistor sensor based on heat loss. Findings - The sintered thick film samples and NTC powder compacts measurements could help in choosing the optimal technology conditions during the production of NTC devices. The NTC segmented thermistors were suitable both for heated sensors and self heated sensors. Practical implications - Low temperature thick film thermistor pastes based on nanometer powder of complex spinel are of interest due to their importance in sensor applications. Originality/value - This work predicts that high temperature pastes of the same material can be realized with characteristics superior to those of low temperature paste such as NTC 3K3 or similar.