Datasheet: Aj Sr04m

For tank level sensing, ensure no obstructions inside the beam cone. For obstacle avoidance, mount multiple sensors to cover blind spots. 6. Temperature Compensation & Accuracy The datasheet specifies ±1% accuracy at 20°C. However, sound speed changes with temperature:

void loop() digitalWrite(TRIG, LOW); delayMicroseconds(2); digitalWrite(TRIG, HIGH); delayMicroseconds(10); digitalWrite(TRIG, LOW); aj sr04m datasheet

For better than 1% accuracy, read a separate temp sensor (e.g., DS18B20) and compute: For tank level sensing, ensure no obstructions inside