Distancing and narrowing cone for AJ-SR04M or JSN-SR04T

thingiverse

This is a cone to narrow down the opening angle of the ultrasonic distance sensors of the watertight SR04 types. It also puts a bit of distance between the sensor and the surface, to compensate for its inferior minimum measuring distance. This object can to be embedded into your actual project/mount. The opening angle is ~10°. Printed it with 1.2 mm walls and 25% infill, but this does not matter too much. The surface may be too rough and reflect sound and spoil your measurement - in this case, wrap someting smooth into the cone, e.g. some plastic sheet (see foto). Works like a charm. Find more details in [my blog](https://projects.webvoss.de/2021/05/28/lessons-learned-measure-water-levels-in-a-barrel-with-sr04-type-sensors/).