V46 - MAT - Middle 3
The MTS Load Frame Station Supervisor (LSS) is required for Performance Level d (PL-d) compliance when severity = S2.

Test System Safety Compliance

Test operator safety is a growing concern. Today’s testing requirements demand that mechanical test systems have the power to apply significant force at startling velocities, and yet function safely for the test operator. To provide the best possible environment for human safety, unplanned actuator movement or unexpected hydraulic pressure states must be detected and controlled quickly.

Although maintaining human safety is a primary objective for most organizations, there is still a great deal of confusion about best practices and compliance requirements for the safe operation of machinery. ISO 13849 offers clear guidelines to define the potential safety risk to humans and to determine the required Safety Performance Level for each situation. This international standard is a common requirement in the EU and is referenced in many other regional safety standards.

Three factors influence the required Performance Level:
1.  Potential severity of injury
2.  Frequency and/or duration of exposure
3.  Possibility of limiting the hazard

Severity of Injury
Slight or Serious
The two options for classifying equipment in the severity of injury category are: slight, indicating the possibility for a reversible injury; and serious, indicating the possibility for irreversible injury or death. Due to the potential for irreversible injury or death when operating test equipment, mechanical test systems are considered to be in the serious classification, which requires a minimum of Performance Level c (PL-c) for compliance.

Frequency and/or Duration of Exposure
Seldom or Frequent
For test equipment, the frequency of exposure is defined as access to the specimen area. Access typically occurs in specimen loading/unloading, alignment etc. The two options for classifying equipment in the frequency of exposure category are seldom and frequent. With respect to exposure time, “seldom” is defined as accessing the specimen area no more than once in 15 minute intervals and the accumulated exposure time does not exceed 1/20 of the overall operating time. Per this definition, the rating would be “F1” for exposure. If the test operator is accessing the specimen more than once every 15 minutes or this exposure exceeds 1/20 of the overall operating time, it is considered frequent exposure. This would be an “F2” rating for exposure. Frequent exposure of an “F2” rating requires a minimum Performance Level d (PL-d) for compliance. Seldom exposure could require a Performance Level of c or d, depending on the possibility of avoiding or limiting the hazard.

Possibility of Limiting the Hazard
Possible or Scarcely Possible
There are two categories for possibility of limiting hazard: possible under specific conditions or scarcely possible. Since hazard limitation, or risk mitigation is usually possible, most test systems can meet this requirement. If there is a use case in which the possibility of limiting the potential hazard is considered scarcely possible and severity = S2, then this case would require a minimum of Performance Level d. If in this same case, the frequency of exposure = F2, then it would require a Performance Level e solution.

In summary, a Performance Level rating of c, d or e is required to meet certain safety standards for most test equipment. Frequency of access and exposure to the test specimen area are the primary factors in determining the required safety performance level. Contact MTS today to discuss your safety requirements.



MTS Systems

14000 Technology Drive
Eden Prairie, MN USA

Tel: 952.937.4000
Tel: 800.328.2255
Fax: 952.937.4515
Email: info@mts.com