Hi,
Please be more specific.
"A sensor" can be almost any device... with any interface you can think of...
It can be:
* a simple resistor ( as current sensor with voltage output)
* a thermocouple (as temperature sensor with voltage output that needs additional circuitry)
* a strain gauge (mechanic sensor with ratiometric output)
* a digital temperature sensor with any kind if digital interface
* a reed relay (as RPM sensor on a bicycle)
* and thousands more
"It has no microcontroller" ....why don't you say "what it has" instead?.
So we have to guess. Does it has a:
* analog voltage meter
* a stepper motor driven gauge
* digital 7 segment display
* PLC
* PC
...
The first idea of a solution to your problem can be to use a ICL7107 (or similar) circuit.
It includes anything from refrence voltage, input amplifier, ADC, decoder, timing generator, display encoder ... to display driver...
Klaus