Quick Verdict
When you're shopping for sensors, encoders, and machine safety gear, the question isn't which sensor is best in general-it's which sensing method actually matches your application. A thru-beam photo eye watches a line of sight and catches an object breaking the beam; a magnetic safety sensor confirms that a guard, gate, or door is in its closed, safe position. Both are new and ready to go, but they serve different jobs. The EMX Industries IRB-MON 2 photo eye and the BNS 33-12ZG magnetic safety sensor sit at opposite ends of the price range, but the real difference is how they protect.
For an outdoor gate, door, or barrier that needs entrapment protection, pick the EMX IRB-MON 2: it's a weather-proof, monitored thru-beam photoeye that pairs with most non-monitored legacy operators. For a machine guard or safety gate that must be confirmed closed on an industrial line, pick the BNS 33-12ZG magnetic safety sensor. In short, choose the sensor that matches the hazard: a clear path to monitor or a guard position to verify.
At a Glance
| Product | Price | Core Job | Standout Detail |
|---|---|---|---|
| EMX IRB-MON 2 Photo Eye | $45.00 | Monitors a line of sight for doors, gates, and barriers | UL325-compliant, IP65-rated, weather-proof thru-beam kit |
| BNS 33-12ZG Magnetic Safety Sensor | $153.00 | Confirms a machine guard or safety gate is closed | Magnetic safety sensor built for industrial automation and control environments |
Where Each Product Wins
The EMX IRB-MON 2 wins for powered doors, gates, and barriers. It is a monitored, weather-proof thru-beam infrared photoeye with an IP65-rated enclosure, and the kit includes transmitter, receiver, integrated hoods, and a removable lens sunshield. That makes it a strong fit for entrapment protection in outdoor and indoor locations.
The BNS 33-12ZG wins for machine guard monitoring. As a magnetic safety sensor, it's suited to industrial equipment, production lines, and automation systems where you need to know that a protective guard is in place before a machine runs.
EMX IRB-MON 2 Photo Eye
The EMX IRB-MON 2 brings a package designed for thru-beam entrapment protection. The kit contains a transmitter, receiver, integrated protective hoods, and a removable lens sunshield, and the housing is IP65-rated for indoor or outdoor use. If you're automating a gate, door, or barrier, this photo eye can work with a wide variety of monitored operators and is compatible with most non-monitored legacy products. The main limitation to keep in mind: it's a line-of-sight sensor. If something interrupts the beam, it responds, but it won't confirm whether a hinged guard is latched. That's not a flaw-it's just the right tool for a different job. For an open path that needs entrapment monitoring, this is the one to consider.
BNS 33-12ZG Magnetic Safety Sensor
The BNS 33-12ZG is aimed at a different kind of safety task. This magnetic safety sensor is made for machine safety control in industrial automation and control environments. If your production line has a sliding or hinged guard that needs to be closed before equipment can operate, this sensor is built for that role. It is intended for use in harsh industrial environments, which matters when the sensor is near moving machinery. The trade-off: it doesn't create a monitored beam across an opening, so it won't catch a person entering through an open doorway. You'd pair it with a guard or gate, not use it as a freestanding presence sensor. If your primary goal is verifying guard position, this sensor makes sense.
Final Choice by Use Case
Choose the EMX IRB-MON 2 photo eye if you need to protect a powered gate, door, or barrier and want a monitored thru-beam solution that can live outdoors. Choose the BNS 33-12ZG magnetic safety sensor if you need to confirm that a guard on an industrial machine is closed before it operates. Your application's hazard-an open path or a guard position-should drive the decision.
