ULS Innovations

Class 4 Conversion Module
(Enabling Pass-Through)

Laser safety standards are well established and relatively harmonized internationally. These harmonized standards establish four broad classifications of laser safety for products. The classifications range from Class 1 in which the laser energy is fully contained within the laser system and the operator is not exposed to any laser energy, to Class 4 in which the laser system does not have containment provisions and the operator can potentially be exposed to high levels of laser energy. To process materials in a Class 1 laser system, the material must fit completely within the laser system enclosure.

The patented Class 4 Conversion Module is an option that allows the user to quickly and easily convert a laser system between fully enclosed Class 1 operation and open Class 4 operation, allowing the user to place oversized objects in the laser system for laser material processing or pass continuous objects such as rolls of material or conveyor systems through the laser system.

This module provides the following benefits to the user:

  • How the Class 4 Conversion Module Works

    ULTRA platforms are equipped with interlocked access doors on either side of the laser system. The optional Class 4 Conversion Module allows use of these platforms with the side doors open by bypassing the safety interlocks on the side doors. With this module installed, the protective system housing is left open, creating the potential for exposure to errant laser energy. Use of this optional device changes the safety classification of the laser system from Class 1, which is considered safe for use under all conditions, to Class 4, which is considered potentially hazardous. Due to these potential hazards, laser safety standards require additional safeguards to be built into laser systems operating in Class 4 mode that are normally not present on Class 1 laser systems. The Class 4 Conversion Module provides these additional safeguards so the laser system meets Class 4 and safety audit requirements.

  • Increased Material Handling Capability

    Awareness of laser materials processing is growing at a rapid pace and as awareness grows, the need to process materials in different form factors and in more productive ways grows as well.

    Prior to the introduction of the Class 4 Conversion Module, which is exclusive to ULS laser systems, there were two methods for handling larger material. One approach was to purchase a Class 1 laser system large enough to completely contain the largest material a user expected to process. This drives up cost and makes for an inefficient use of space and resources, especially if oversize parts are not processed very frequently. The other approach was to purchase an open bed, certified Class 4 laser system. The drawback of operating an always open Class 4 laser system is the added risk and liability of operating continuously in Class 4 mode. Also, there is the burden of the additional safety protocols the user must practice along with the cost and maintenance of safety equipment. In some locations, routine inspections by safety inspectors may even be required to operate Class 4 laser systems.

    An ideal solution for occasional processing of larger materials is a smaller Class 1 laser system that can be legitimately operated in Class 4 mode when needed. Less scrupulous manufacturers will look the other way when customers bypass safety interlocks on Class 1 laser systems or even hint to customers that this is an acceptable practice to process oversized materials. However, a Class 1 system with safety features bypassed is not equipped with the required safety features to operate in Class 4 mode and would never pass safety audits. ULS has solved this problem with its unique, patented Class 4 conversion module which adds all of the required safety features necessary to operate an open laser system in Class 4 mode. This module can be added and removed from the laser system in minutes thereby allowing the user to operate in true Class 4 mode only when necessary - providing complete flexibility.

    An additional benefit of the Class 4 Conversion Module is the ability to convert a laser system to operate permanently in true Class 4 mode. This feature, in conjunction with the ULS Automation Interface option, allows a laser system to be safely integrated into a high productivity manufacturing environment. Laser based production processes can be developed on a Class 1 laser system in small batches and the same laser system can be easily converted to higher productivity with the addition of material handling equipment such as shuttles or roll feeds without a large investment in new and different laser systems.

  • Improved Safety and Reduce Liability

    There are many mandatory safety measures required under internationally recognized laser safety standards. These safety measures must be complied with when operating a Class 4 laser system. Certain safety measures are the responsibility of the manufacturer and are integrated into the optional Class 4 Conversion Module, including the following:

    • Remote Interlock Connection
      A means of remotely connecting to the interlock circuit of the laser system allowing connection of remote switches to the laser system for deactivating the laser. This feature must be used to connect an interlock switch to the doors of the designated room in which the laser system will be operated so that the laser is automatically deactivated when the doors are open.
    • Key Control
      A removable key that prevents unauthorized operation of the laser system when in Class 4 mode.
    • Laser Energy Emission Warning Device
      A visible warning light that indicates when the laser is capable of emitting laser energy.
    • Attenuator
      A mechanical device to block emission of laser energy. This device takes the form of a shutter which is manually operated.
    • Class 4 Warning Label
      A Class 4 warning label to indicate the laser system is classified as Class 4.

    In addition to the requirements placed on the manufacture of Class 4 laser systems discussed above, there are certain operational safety measures that are the responsibility of owners of the laser systems operating in Class 4 mode. As part of the sales process for purchasing a Class 4 conversion module from ULS, information is provided to the user describing their responsibilities and ULS experts are available to answer any questions. These safety measures are mandatory for operation of Class 4 laser devices under Federal and State law in the United States as well as under the laws of most other countries. Many of these safety measures are outlined in ANSI Standard Z136.1 “American National Standard for the Safe Use of Lasers” or in equivalent standards available in most other countries, such as the European Standard EN 60825-1. Other safety measures may be required by state and/or local authorities, for example, the Regulation BGV B2 on laser beams of the German Employer’s Liability Insurance Association. It is the responsibility of the Owner to understand and adhere to these laws. A brief synopsis of the most common safety requirements addressed to Owners of a Class 4 laser is outlined below:

    1. In any facility in which a Class 4 laser system is to be operated, an individual must be designated as a Laser Safety Officer (“LSO”) who will assume the authority and responsibility to monitor and enforce the control of laser hazards. The individual designated as the LSO should be trained in laser safety and aware of all safety measures set by law. There are many avenues available to acquire this training. Recognized sources of this training are the Laser Institute of America (, the Employer’s Insurance Liability Associations in the European countries or, laser safety associations within Owner’s country or territory.
    2. The Owner of the Class 4 laser system will be responsible for creation of a controlled area in which a Class 4 laser system will be operated. A controlled area is an area designed to fully contain the laser energy potentially escaping from a Class 4 laser system and with measures in place to prevent unauthorized personnel from entering the area including lighted warning signs outside the designated and controlled area and interlocks on entryways.
    3. The LSO will be responsible for designating and training all personnel authorized to operate, maintain or service a Class 4 laser system. It will also be the responsibility of the LSO to take measures to inform and restrict all unauthorized personnel from access to a Class 4 laser system.
    4. The Owner of the Class 4 laser system will be responsible for identifying and providing to all authorized personnel any protective equipment such as specially designed eyewear, protective equipment and clothing needed when operating, maintaining or servicing a Class 4 laser system. Further, the Owner will ensure that no juveniles operate the laser.
    5. Mirrors, lenses and other reflecting or refracting materials should not be used around or processed in a Class 4 laser system. Adequate measures must be taken to control these materials around Class 4 laser systems.
    6. The LSO will be responsible for auditing all safety measures on a regular basis. This includes regular retraining of authorized personnel, serialization and regular inspection (and replacement when necessary) of all special eyewear and clothing and regular inspection of all safety measures surrounding the controlled area in which a Class 4 laser system is operated. The LSO may be required to maintain records as necessary to prove compliance.
    7. The LSO will be responsible for regular medical surveillance of all authorized personnel operating a Class 4 laser system. This can include but is not restricted to mandatory annual eye exams, for example.
    8. Class 4 lasers must not be used at tradeshows or exhibitions.

    The above list is not to be considered exhaustive. Other mandatory safety measures may be applicable which will vary from state to state and country to country. It is the responsibility of the owners of a Class 4 laser system and the owners of the facility in which it will be operated to identify and comply with all regulations pertinent to their locale. In some states, for example, anyone wishing to operate a Class 4 laser device must register with the state energy regulatory agency, pay annual fees and submit to annual inspections. There may be penalties involved for non-compliance. The United States Occupational Safety and Health Administration (“OSHA”) has also adopted rules for safe use of lasers in the workplace. The LSO must comply with all Rules and Regulations set by law.

    A user must carefully weigh the risks and additional regulatory safety burdens of safely operating a laser system in Class 4 mode. However, if the need arises to operate in Class 4 mode in order to process oversized material or more efficiently move material through a laser system, a user can be confident in ULS solutions. By taking advantage of the Class 4 conversion module, a user’s laser system will have all of the safety features required to operate safely in class 4 mode and pass safety audits. User and owners will also receive all of the information and help they need to understand and follow proper safety practices and minimize business liability.