USD 108.80
Omron E3T-SR42 2M is a compact NPN retro-reflective sensor with an included E39-R4 reflector and a 30 to 200 mm sensing range.
The Omron E3T-SR42 2M is an ultracompact retro-reflective photoelectric sensor with a 2 m pre-wired cable, M2 mounting and the E39-R4 reflector included. With that reflector, the specified sensing distance is 30 to 200 mm; the sensor uses a 650 nm red LED and an NPN open-collector Dark-ON output. It has an IP67 enclosure rating and a 1 ms maximum response time. Omron listed this exact model as selling and standard-stock on 2026-10-05, with a △ stock indicator.
A compact retro-reflective sensor with an included reflector for detecting opaque objects.
| Parameter | Value |
|---|---|
| Product type | Ultracompact retro-reflective photoelectric sensor |
| Sensing method | Retro-reflective, without MSR function |
| Sensing distance | 30 to 200 mm with E39-R4 reflector |
| Alternative reflector range | 10 to 100 mm with E39-R37-CA reflector |
| Standard sensing object | Opaque object, 27 mm min. diameter |
| Minimum sensing object | 2 mm min. diameter at 100 mm sensing distance |
| Directivity | 2 to 20 degrees |
| Light source | Red LED, 650 nm |
| Supply voltage | 12 to 24 VDC ±10%; ripple 10% p-p max. |
| Current consumption | 20 mA max. |
| Control output | NPN open collector, 26.4 VDC max., 50 mA max. |
| Operation mode | Dark-ON |
| Response time | 1 ms max. (operate and reset) |
| Protection rating | IEC 60529 IP67 |
| Operating temperature | -25 to +55°C, no icing or condensation |
| Connection | Pre-wired, 2 m cable |
| Mounting | M2; M2 × 14 set screw and nut supplied |
| Included reflector | E39-R4 |
| Housing material | Polybutylene terephthalate (PBT) |
| Lens material | Methacrylic resin |
| Physical Weight (kg) | 0.020 (approx., packaged). |
| Dimensions L x W x H (cm) | See the Omron E3T-SR4□ dimension drawing; no consolidated L × W × H value is stated in the text data. |
| Supply status | Active; Omron listed E3T-SR42 2M as selling and standard-stock on 2026-10-05; stock indicator 〇. |
Engineering suggestions require suitability checks for your installation.
A part passing between the sensor and its reflector interrupts the returned light.
Install the included E39-R4 reflector within the specified 30 to 200 mm sensing distance and check detection with the actual target.
The small M2-mount sensor can monitor an object path where a separate reflector can be fitted opposite the sensor.
Set the reflector alignment and sensor position within the published range, then verify the target response and installation conditions.
