- Machine vision
- Optical metrology
- Application engineering
- CAGE Code 0QC65
Safety mats are part of a complete safeguarding system. Proper selection depends on the machine, stopping time, approach direction, access paths, control architecture, and required safety performance.
ASO describes SENTIR mats as durable polyurethane devices available with several slip-resistant surface options and configurable shapes and zones.
SENTIR safety mats create a pressure-sensitive detection zone around potentially hazardous machinery. When a person steps onto the mat, an internal contact system changes state and sends a signal to the machine’s safety-control system.
Depending on the machine and its validated safety design, that signal may be used to stop hazardous movement or transition the equipment to a safer operating condition.
Unlike fencing and other physical barriers, safety mats preserve visibility and provide open access when the machine is in a safe state. They can be used individually or combined to monitor larger and unusually shaped areas.
The final machine response, reset behavior, diagnostics, and safety performance depend on the selected components and the design of the complete safety-related control system.
Create a monitored approach zone around robots, presses, assembly equipment, and automated machinery.
Detect when a person steps into an area where hazardous movement or machine operation may occur.
Confirm that an operator remains at a required workstation or control position during a process.
Use pressure-sensitive switching for appropriate non-safety applications such as access control, guidance, exhibits, lighting, or other presence-driven functions.
Low-profile floor-mounted mats do not introduce the same visual obstruction as full-height fencing—an advantage in areas shared with operators, material-handling equipment, or forklifts.
Mats can be configured in different shapes and combined into larger detection zones to accommodate the machine and its surrounding floor plan.
SENTIR mats use a sealed polyurethane construction. Available surface treatments include textured polyurethane, aluminum checker plate, stainless steel, and other slip-resistant options, depending on the model and application.
A mat can identify entry into a restricted area or confirm continued presence at a designated position.
ELMON switching devices provide the interface between SENTIR safety mats and the machine-control system. They monitor the connected sensor circuit and communicate a change of state when the mat is activated.
Depending on the selected relay, monitoring can also identify conditions such as a cable interruption or circuit fault. Available models differ in their inputs, outputs, enclosure, power requirements, safety category, and performance level, so the relay must be matched to both the sensor and the required safety function.
The first and by far the most important consideration is the calculation of the safety distance. There is a minimum mat size that should be placed between a worker and a hazardous motion. Many users will ‘‘eyeball’‘ the application, look at the area where a machine operator would stand and say, ‘‘that looks like it needs a 24-inch wide mat.’‘ It may not be enough.
In standard B11.19, the American National Standards Institute (ANSI) states that ‘‘The safety mat device shall be located such that the operator cannot reach the recognized hazard before hazardous motion of the machine has ceased.’‘
Unfortunately, the ANSI standard stops there. To figure out how much mat you need between a machine and a worker, it’s necessary to refer to the standard EN 999. This standard provides a formula for determining the correct mat size for a specific hazard. The formula is similar in nature to another calculation, which some readers may be familiar – the mounting distance formula for a safety light curtain.
The mat formula reads as follows: S = (63 in./sec. x T) + (47.2 in. – 0.4H)
where: S = The minimum distance from the danger zone to the detection zone in inches. This calculation assumes that the approach of a person toward a dangerous area is at walking speeds. T = t1 + t2 T = The overall system stopping time. t1 = The maximum time between the actuation of the safety mat and
the controller output relays being in the de-energized state. t2 = The response time of the machine being guarded. The time required to stop the machine or remove the risk after receiving the output signal from the mat system. H = The distance above the reference plane (floor) in inches. When mats are mounted on the floor, H = 0.
Example: As an example, let’s say the stopping time of the guarded machine is 0.300 seconds. The response time of the mat system is 0.025 seconds. The safety mat is to be mounted at the reference plane (floor).
S = (63 in./sec. x T) + (47.2 in. – 0.4H) or S = (63 in./sec. x (t1 + t2)) + (47.2 in. – 0.4H)
Therefore: S = (63 in./sec. x (0.300 sec. + 0.025 sec.)) + (47.2 in. – (0.4H x 0.0in.)) S = (63 in./sec. x 0.325 sec.) + (47.2 in. – 0.0 in.) S = 20.5 in. + 47.2 in. S = 67.7 in. or 1720 mm
This calculation specifies that the distance starting at the mat edge furthest from the hazardous location should be at least 67.7 inches. This also implies that the floor area, from a distance of 67.7 inches to the hazardous location must be guarded by mats or other means, such as fencing, to prevent any undetected access to the hazardous location. Using this formula will usually result in a larger safety mat specification than most people would estimate.
Minimum Detection Zone
The distance a person walks is generally a factor of the walking speed and the stride length. As we have already seen, the positioning of safety equipment, determined by these calculations, assumes a person is walking. The stride length affects the minimum
size of the mat detection zone. The EN 999 standard has determined that this dimension is equal to 750 mm or 29.5 inches. Thus, the minimum size of a safety mat, measured toward the direction of movement should be at least 29.5 inches.
