Compact Dual-Mode Photoelectric Sensors Save Space and Cut Cost in Non-Contact Hand-Sanitization Equipment


Automated, non-contact operation has become the norm for hand sanitization, and dispenser manufacturers need robust, affordable sensors to detect the presence of an individual’s hands. Dispensing soap and water traditionally requires two different sensors for accurate delivery, but modern systems use identical sensors for either application, reducing spares inventory and cutting cost. Designers require compact, user-programmable dual-output sensors capable of withstanding mechanical shock and fluid ingress, while offering an attractive price/performance profile.

Customer Values

  • Diffuse-mode sensors with background suppression and a sensing distance of up to 250 mm are ideal for hand detection

  • Compact M18-diameter devices with 55 mm overall length fit snugly in a typical, tightly packed dispensing head

  • Rugged stainless-steel housings and shatter-resistant PMMA optics, rated to IP67, protect against mechanical shock and fluid ingress

  • IO-Link functionality provides two discrete, programmable outputs that trigger dispensation of either soap or water

  • Robust, versatile sensors represent exceptional value for money, with a price/performance profile that exceeds expectations

  • Customized versions with bespoke functionality are available for specialized applications

Specific Product Advantages

  • Robust metal-bodied M18M photoelectric sensors offer increased protection in the harshest environments

  • Shatter-resistant PMMA optics are lighter and tougher than glass with a focused beam on all versions

  • Sensors with stainless-steel housings devices are resistant to washdown and process fluids

  • Exclusive ASIC technology delivers compact design with superior sensing performance and best-in-class sensing distances

  • Best-in-class sensing distances ensure maximum flexibility for designers

  • User-configurable devices with IO-Link functionality are ideal for easy integration

  • Unrivalled price/performance ratio offers exceptional value for money

  • Comprehensive range of cables and mounting brackets available

  • Enhanced −25°C to +65°C operating range

Customer Application

 Since the advent of Covid-19, hand sanitization has become an increasingly high-profile aspect of personal hygiene and a permanent feature of everyday life. Automated, non-contact operation is the norm for speedy, safe hand-washing, using either soap and water or an alcohol-based sanitizer. Dispenser manufacturers need robust, affordable sensors to detect the presence of an individual’s hands and trigger delivery of soap, water or sanitizer on demand.

Soap-and-water dispensers have dual delivery systems, requiring two sensors for accurate sequential dispensation, each with a unique, application-specific operating profile. Additional constraints arise from the nature of the application: The physical design of a typical dispensing head imposes tight limits on the sensor size, while the presence of liquid soap, water or sanitizer necessitates a high degree of protection against fluid ingress.

Growing demand for low-cost, compact dispensers forces designers to consider adopting a single, programmable sensor that suits both applications, reducing spares inventory and cutting cost. Key to adopting this approach is the availability of a compact dual-output sensor with user-programmable functionality, enabling the same type of device to trigger either soap- or water-dispensation. Cost constraints also exert significant influence in sensor selection, limiting the choice to devices with an acceptable price/performance profile.

Customer Solution

 Compact, robust and featuring IO-Link multi-mode functionality, Contrinex’s Standard M18M metal-bodied photoelectric sensors tick all the boxes for dispenser manufacturers. These diffuse-mode sensors with background suppression are practically insensitive to a target’s size, color, shape and texture, and with a sensing distance of up to 250 mm, they are ideal for the application.

With an overall length (including M12 right-angle connector) of 55 mm, these highly versatile devices fit immediately adjacent to the soap or water nozzles in typical, tightly packed dispensing heads. Featuring Contrinex’s exclusive ASIC technology, they offer best-in-class sensing distances, while rugged stainless-steel (V2A/AISI 303) housings and shatter-resistant PMMA optics, together rated to IP67, provide excellent protection against mechanical shock and fluid ingress.

IO-Link functionality, a no-cost option on PNP devices, provides two discrete user-programmable outputs following detection of a hand beneath the sensor. For soap dispensation, a one-shot output delivers a single pulse to trigger delivery of soap; alternatively, the second output maintains the flow of water as long as a target is detected.

To prevent false triggering, a user-defined time delay may be applied before water starts to flow, while a signal ‘stretch’ (also user-defined) allows it to continue for a short while after the hand is removed. IO-Link also allows real-time access to process data as well as additional functionalities that include sensitivity adjustment, event flags and sensor-temperature measurement.

Designed with the needs of OEMs and system integrators in mind, Contrinex M18M metric-threaded metal-bodied photoelectric sensors are not only affordable, but meet designers’ needs for a robust, versatile solution with a best-in-class service life. They represent exceptional value for money, while offering a price/performance profile that exceeds expectations. Customized versions with bespoke functionality are also available for specialized applications.