Hello,
We are deploying BTS-MP1 sensors as door-open/close contacts in a customer product (small-scale agricultural IoT). One of our field units appears to be failing to detect the paired magnet despite correct physical alignment and spacing, and we suspect magnetic polarity is the cause.
Could you confirm the following about the BTS-MP1’s internal magnetic sensor:
- Is the sensor polarity-sensitive — i.e., will it respond to only one magnetic pole (N or S) facing the sensor, and ignore the opposite pole?
- If yes, which pole (North or South) must face the marked detection point on the BTS-MP1 enclosure for the sensor to trigger?
- Is there a tolerance for off-axis or angled magnet placement, or does the magnet’s pole axis need to be normal to the sensor face?
- Do you have a recommended magnet specification (grade, dimensions, gauss rating) and a recommended maximum air-gap distance for reliable detection?
For context: the magnets we are using are standard neodymium pucks shipped with the unit. We want to make sure our installation instructions to end customers correctly specify the magnet orientation so this is not a recurring field issue.
Thanks,
Tennis Smith
SVW LLC
Hello,
Thank you for using our community forum.
The Eye sensor is not polarity sensitive. They act like reed switch which any magnet polarity will trigger the sensor components. It can trigger by using any available magnets (not necessarily out magnets). For the installation, it is recommended to follow our installation procedure and always check if the magnet being detected by Eye sensor before done any permanent mounting.
The EYE Sensor detects the presence of a magnetic field and reports it as a binary state (0 or 1), just like a reed switch used in door/magnet sensors:
-
0 = No magnet detected
-
1 = Magnet present
This makes it functionally equivalent to a reed switch for applications like door open/close detection or proximity sensing.
While the output behavior is similar, the EYE Sensor uses a hall sensor for magnetic field detection rather than a mechanical reed switch. Hall sensors are solid-state electronic components that detect magnetic fields without moving parts, offering advantages in durability and reliability compared to mechanical reed switches.
Regards
Muaz.Z
Hi Muaz,
Thanks for the quick response — I want to push back gently before I act on this.
A mechanical reed switch is genuinely polarity-agnostic. A Hall-effect IC usually isn’t — most are unipolar (one pole only); only omnipolar variants behave like a reed. So “acts like a reed switch” and “any polarity triggers it” aren’t the same claim.
On the bench: a neodymium magnet held ~2 mm from a BTS-MP1, rotated through multiple orientations and flipped end-for-end, does not change the reported state. Photo attached. That’s hard to square with an omnipolar sensor.
Could you confirm:
- Is the Hall IC inside unipolar, bipolar, or omnipolar?
- Which face of the enclosure is sensitive, and along what field axis?
- Recommended magnet grade / minimum field strength at the sensing face?
Thanks,
Tennis
