Omron E3S-R31 Retroreflective Optical Sensor - Equivalent & Substitute Parts

Part Overview

The Omron E3S-R31 is a retroreflective, polarized optical sensor designed for detection applications requiring adjustable sensing distances from 100mm to 1m. The sensor features PNP output with selectable Dark-ON/Light-ON operation, operating across a 10V to 30V supply range with 1ms response time. The E3S-R31 is classified as obsolete, making identification of functionally equivalent active alternatives essential for new designs and system maintenance.

Key Parameters

Parameter	E3S-R31 Specification
Sensing Method	Retroreflective, Polarized
Sensing Distance	100mm ~ 1m (3.937" ~ 39.370")
Voltage Supply	10V ~ 30V
Output Configuration	PNP - Dark-ON/Light-ON Selectable
Response Time	1ms
Light Source	Red (700nm)
Connection Method	Cable
Ingress Protection	IEC IP67
Operating Temperature	-25°C ~ 55°C
Adjustment Type	Two-Turn Endless Adjuster
Product Status	Obsolete

Substitute Part Grouping Explanation

The E3Z-B82 qualifies as a functional substitute based on the following critical parameters:

Sensing Method: Both sensors employ retroreflective detection, enabling equivalent optical path operation
Output Configuration: Both provide PNP output with Dark-ON/Light-ON selectable modes, ensuring compatible signal logic
Response Time: Identical 1ms response time maintains system timing requirements
Light Source: Both use red wavelength illumination (700nm vs 680nm), within acceptable optical spectrum tolerance
Connection Method: Both utilize cable connections for identical installation compatibility
Ingress Protection: Both meet IEC IP67 rating for equivalent environmental sealing
Operating Temperature: Identical -25°C to 55°C range ensures thermal compatibility

Key Difference: The E3Z-B82 extends sensing distance to 2m (versus 1m maximum on E3S-R31) and operates within a narrower 12V to 24V supply range. The E3Z-B82 features single-turn adjustment versus the two-turn endless adjuster on the E3S-R31.

Parameter Comparison

Parameter	E3S-R31	E3Z-B82	Compatibility Notes
Sensing Method	Retroreflective, Polarized	Retroreflective	Both retroreflective; E3Z-B82 lacks polarization specification
Sensing Distance	100mm ~ 1m	2m	E3Z-B82 provides extended range; compatible for applications within 1m
Voltage Supply	10V ~ 30V	12V ~ 24V	E3Z-B82 range is subset of E3S-R31; verify supply voltage compatibility
Output Configuration	PNP - Dark-ON/Light-ON Selectable	PNP - Dark-ON/Light-ON Selectable	Fully compatible
Response Time	1ms	1ms	Fully compatible
Light Source	Red (700nm)	Red (680nm)	Both red spectrum; minor wavelength difference acceptable
Connection Method	Cable	Cable	Fully compatible
Ingress Protection	IEC IP67	IEC IP67	Fully compatible
Operating Temperature	-25°C ~ 55°C	-25°C ~ 55°C	Fully compatible
Adjustment Type	Two-Turn Endless Adjuster	Single-Turn	Different adjustment mechanism; E3Z-B82 offers faster calibration
Product Status	Obsolete	Active	E3Z-B82 is actively manufactured and supported

Engineering Selection Recommendations

The E3Z-B82 is the designated substitute for the obsolete E3S-R31 based on functional equivalence across all critical sensing and output parameters. The E3Z-B82 maintains active product status with ongoing manufacturer support, ensuring long-term availability and technical documentation access.

Selection Criteria:

Supply Voltage Verification: Confirm system supply voltage operates within the E3Z-B82 range of 12V to 24V. Systems requiring operation below 12V or above 24V cannot use this substitute.
Sensing Distance Application: The E3Z-B82 maximum 2m range exceeds E3S-R31 capability. Applications requiring sensing distances up to 1m are fully compatible.
Adjustment Requirements: The E3Z-B82 single-turn adjuster differs from the E3S-R31 two-turn design. Evaluate whether application requires fine-tuning capability of the endless adjuster.
Compliance Status: The E3Z-B82 carries RoHS Compliant certification, providing regulatory advantage over the obsolete E3S-R31.

Frequently Asked Questions (FAQ)

Q: Can the E3Z-B82 directly replace the E3S-R31 in existing installations?

A: Direct replacement is possible when system supply voltage operates within 12V to 24V and sensing distance requirements do not exceed 1m. Mechanical mounting and cable connector compatibility must be verified against specific installation documentation.

Q: What is the impact of the different adjustment mechanisms?

A: The E3S-R31 two-turn endless adjuster provides continuous fine-tuning capability. The E3Z-B82 single-turn adjuster offers faster initial calibration but with reduced granularity. Application sensitivity to distance calibration determines suitability.

Q: Are there wavelength differences between the red light sources?

A: The E3S-R31 operates at 700nm while the E3Z-B82 operates at 680nm. Both wavelengths fall within the red spectrum and are compatible with standard retroreflective targets. Reflector material compatibility should be verified for critical applications.

Q: Does the E3Z-B82 polarization specification affect substitution?

A: The E3Z-B82 specification does not explicitly reference polarization, while the E3S-R31 is polarized. Applications relying on polarization filtering for background light rejection should evaluate E3Z-B82 performance in the specific optical environment.

Q: What packaging differences exist between these sensors?

A: The E3S-R31 packaging specification is not provided. The E3Z-B82 is supplied in bulk packaging. Verify connector type and cable length compatibility with system requirements.

Q: Is the E3Z-B82 suitable for new design implementations?

A: Yes. The E3Z-B82 active product status, RoHS compliance, and functional equivalence make it the appropriate choice for new designs requiring retroreflective PNP optical sensing with 1ms response time.

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