Temperature  measurement (sensing) and monitoring will be economical and straightforward if we apply the input of  TC9400 V/F converter with a voltage from output of a probe, such as shown in diagram below. The V/F output is simply counted to display the temperature. The TC9400 can be used to modulate an RF transmitter for a long distance data transmission.

TEMPERATURE METER circuit schematic

The temperature display should have latch control, means that the counting process is not transparently displayed on the seven segment until a latch signal is triggered to transfer the counting result to be displayed. After latched, the reset signal would reset the counter without affecting the latched display. [Circuit’s schematic diagram source: Microchip Datasheet]