IEC 60825-12:2004 pdf free download

IEC 60825-12:2004 pdf free download
IEC 60825-12:2004 pdf free download.Safety of laser products
4.3 Classification
Classification of the optical transmitter is determined by the manufacturer based on measurement or analysis of accessible optical radiation as specified in IEC 60825-1. Both the primary beam and any alignment or beacon beams accessible during operation must be considered in classifying the product and determining its use in appropriate locations as indicated in Table 1. Verification tests shall be made under the appropriate conditions, e.g. at accessible positions, using the limiting apertures and time durations specified in IEC 60825-1.
FSOCS equipment may be designed to operate with an APR system so that the emitted power is reduced when a human crosses into the NHZ, or NHZ-Aided, (see 4.3.1). For FSOCS applications, it is permissible to determine classification of FSOCS transmitters and the access level assignment based on the emission that is accessible following a 2-second delay from the time of initial human exposure. During the 2-second period the MPE, measured using viewing conditions without optical aids shall not be exceeded for equipment classified as Class 1, 2，1M or 2M. For viewing conditions without optical aids refer to Table 7 of IEC 60825-1. An APR system is only permitted on transmitters that are classified as Class 1， 2, 1M or 2M with the APR system enabled.
NOTE Rationale for 2 s: Because of the difficulty of a person with binoculars or other optical aid to fully align with a free space optical beam, it is not reasonably foreseeable that a person could intercept the beam’ s full power within 2 s.
4.3.1 Automatic power reduction mechanisms (APR)
An APR system is a feature that a manufacturer may supply with an FSOCS transmitter by which the accessible power is reduced to a specific level within a specific time, whenever there is an event that could result in human exposure to radiation above the applicable MPE, e.g. a person intercepting the beam or even a very small portion of the beam that would accommodate a 50 mm, 25 mm, 7 mm or 3,5 mm or other aperture, as described in Table 10 of IEC 60825-1.
The operation of an APR system affects the classification of the FSOCS transmitter and the access level at monitored locations as described in 4 .4. The APR only refers to that mechanism that monitors the NHZ or NHZ-Aided and reduces power. It does not extend to installation protection systems used for limiting access in a unrestricted, restricted or controlled location.