New protective-device installation
Establish or verify the installation distance when adding a light curtain, scanner, safety mat or comparable presence-sensing device.
Protective-device verification
Stop-time testing for light curtains, scanners and safe access.
A protective device can only be positioned correctly when the machine’s stopping behaviour and the relevant approach assumptions are understood. We measure response and stopping time, record the test conditions and use the result to support a defensible safeguarding distance.
Customer outcomeSafe access · reliable production
- Base
- Oxfordshire
- Coverage
- Great Britain
- Contact
- 01865 416840
Direct answerWhy is machine stop-time testing needed?
Why is machine stop-time testing needed?
Stop-time testing measures how long a hazardous machine movement takes to reach a safe condition after a protective device or safety function is actuated. The measured response, together with the applicable approach speed, intrusion allowance and device characteristics, informs the minimum distance between the sensing field or access point and the hazard. It is particularly relevant to light curtains, laser scanners, pressure-sensitive devices and openings where a person could reach the danger zone before motion has stopped.
Where this solution is used
Designed around the machine and the work people perform.
The scope is developed from actual access, process and maintenance needs rather than a standard panel count.
Machine modification
Recheck stopping performance after changes to drives, tooling, brakes, control logic, payload, process speed or guarding layout.
Periodic verification
Create a repeatable baseline and detect deterioration where the risk assessment or maintenance plan requires ongoing stop-performance checks.
Engineering decisions
What must be resolved before manufacture or modification.
These decisions interact. A change to stopping, door use, material flow or maintenance can alter the complete safeguarding concept.
- 01
Test point and hazardous motion
Define which axis, tool or process creates the limiting hazard and where the stop should be initiated.
- 02
Operating conditions
Test representative speed, load, mode and process conditions rather than an artificial low-demand state.
- 03
Safety-function path
Identify the complete route from sensor actuation through logic and outputs to the final stopping element.
- 04
Measurement method
Use suitable equipment, repeated trials and a documented trigger method that produces traceable results.
- 05
Distance calculation
Apply the relevant standard methodology, device resolution and supplementary distances to the measured value.
- 06
Retest interval
Set a review trigger based on risk, brake wear, maintenance, modification and the consequences of performance drift.
Site and application review
Information we assess.
- Maximum production speed and load
- Brake or drive condition
- Machine control response
- Sensor response and resolution
- Reach-over and reach-through possibilities
- Floor level and approach direction
- Muting or bypass modes
- Environmental effects and repeatability
Typical project scope
What Oxford Machine Guarding can provide.
Deliverables are agreed before work starts. We can support a defined component or take responsibility from site survey through design, installation and documented handover.
Technical reference: ISO 13855:2024. The current applicable edition and project context must be confirmed for each calculation.
- Documented test method and machine condition
- Repeated stop-time measurements
- Worst-case recorded result
- Safety-distance calculation support
- Photographic identification of test locations
- Recommendations where the installed distance is inadequate
- Retest triggers and maintenance considerations
- Optional protective-device relocation or integration scope
