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ISO 11837-2011 pdf free download

ISO 11837-2011 pdf free download.Machinery for forestry — Saw chain shot guarding systems — Test method and performance criteria
Materiel forestier— Système de protection contre léjection d’élóments de chaines de scie — Méthode d’essai et critères de performance.
4.2 Drive sprocket
The test runs shall be performed within the manufacturer’s operating specifications and with the drive sprocket available in the original cutting attachment that provides
a) the highest saw chain speed, and
b) the largest distance between the drive sprocket and the saw chain shot guarding system.
4.3 Saw chain
A saw chain that is recommended in the harvester-head or grip-saw manufacturer’s instruction handbook for use together with the guide bar and drive sprocket shall be chosen. One of the following reference saw chain dimensions shall be preferred:
— saw chain with 0,404 inch pitch, thickness 1,6 mm;
— saw chain with 0,404 inch pitch, thickness 2,0 mm;
— saw chain with 3/4 inch pitch, thickness 3,1 mm.
The number of drive links is detemined in relation to the guide bar length.
5 Reference panels
There shall be two reference panels (see items la and lb in Figure 1) with a width of 400 mm ± 20 mm and a length of 1 000 mm ± 20 mm, consisting of plastic film, kraft paper or similar material. The location and orientation of the two reference panels shall be as described in Figure 1.
6 Pre-calibration of test arrangement
The pre-calibration is performed in order to secure the statistical confidence of the test results.
Ten test runs without the saw chain shot guarding system mounted shall be performed to evaluate the functioning of the test arrangement. Perform the test procedure specified in Clause 8, but without assembling the saw chain guarding system. Run five test runs at 0,8 times the maximum design saw chain speed, C, and five test runs at 1,2C’. At least four of the five test runs at each speed shall result In a saw chain shot through one of the reference panels.
If a complete harvester head or grip saw is tested, some parts of the saw chain shot guarding system and obstacles (see 7.3) will have to be removed prior to the pre-calibration tests, to ensure that saw chain shots are created.
If the criterion of at least four saw chain shots out of five test runs is not met, the test arrangement shall be modified and the pre-calibration repeated until this criterion is met.ISO 11837-2011 pdf free download.

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