In many factories and machine shops safety mats are an ever-present ‘old faithful’ friend – relied upon to protect workers from hazardous processes such as stamping, cutting and pressing. Simple? Yes. Dependable? Hopefully. Safe? Maybe. Good value? Debatable. Changing to a laser scanner may cost less than two mats and have additional benefits, be easy to use, and ensure compliance with the latest machine safety directives.

Stepping on it

One of the biggest issues with safety mats is that they stop working properly because people repeatedly step on them – after all, that’s what they’re designed to for. The compressive resilience of the mat changes with age and use, becoming inherently less safe. Worn or old mats may not compress enough except under ever increasing loads and the insulating materials degrade causing false alarms. The reliability of the mat can be damaged by heavy items such as forklifts, trolleys, loaded pallets, and stillages. Punctures can allow fluids such as hydraulic oils or chemicals to compromise safety. All this leads to downtime, frequent replacement and growing uncertainty of the risks involved. The latest machine safety directives concentrate on speed of response of a safety device compared with the distance moved by an operative. If the mat response is uncertain can you be sure the machine will stop quickly enough?

Time of flight measurement

The safety laser scanner is a small, all-in-one device, with very precise and easily programmable operation. Safety laser scanners can define protective and warning fields, also referred to as zones or areas. These zones are freely programmable and can be changed easily by authorised personnel. By having warning fields, machine down time can be reduced significantly, because an approaching person can be warned by an audible or visible alarm before the machine needs to be stopped.

Fail safe

Laser safety scanners are reliable and durable. They will not wear out with use in the same way as a mat would do and, as a non-contact technology mounted above the ground, they are less likely to be damaged. A laser scanner is a fail-safe device not subject to gradual deterioration; it either works or doesn’t. If a mat fails because of physical contact, it is likely that a machine will have to be shut down, depending on a company’s internal processes and procedures regarding safeguarding. This shut down will remain in effect until the safety mat is replaced by one in stock or another is shipped and mounted. This process takes time and disrupts production, in addition to incurring capital costs. With a safety laser scanner, the scanning field can be configured to whatever is required. Static obstructions like walls or pillars can be swiftly taught-in and the same scanner is easy to reconfigure whenever a change is made. If the device is damaged, it is frequently only the scanner head that needs changing; a simple plug-in replacement. The safety settings are retained in the system plug memory and are automatically downloaded to the new scanning head.

Few exceptions

Safety laser scanners are designed for reliable operation in challenging environments where there is extreme dirt or heavy moisture and can be IP67/69 protected. As laser safety scanning technology becomes accessible and universal, the argument for change gets ever stronger. There may be some applications where a simple step-on mat is a better choice, but this is likely to be only in extreme conditions where a safety mat will still need frequent replacement.