I wonder if it's possible to use HC-SR04 ultrasonic distance-sensors in extreme temperatures like -30 Celsius? Can't find any datasheet that says what working temp it has.
Do anyone have experience of using ultrasonic distance-sensors in extreme temperatures?
Even if the sensor could stand such temperature, you would have to check out it’s accuracy at such extremes. The speed of sound is effected by temperature so you would need to determine what impact that would have and what it would take to compensate for it.
Aha, thanks for the fast respond!