BS 5371:1990 pdf free.Standard method of measurement of lampcap temperature rise.
BS 5371 The draught-proof enclosure is rectangular, with adouble skin on the top and on at least three sides,and with a solid base.The double skins are ofperforated metal, spaced apart approximately 150 mm, with regular perforationsof 1 mm to 2 mm diameter, occupying about 40 % ofthe whole area of each skin. The internal surfaces are painted with a matt paint.The dimensions of the enclosure shall be such that the ambient temperature within the test enclosurewill not exceed 40C while the test is being run.Toachieve this condition the three principal internaldimensions shall be preferably at least 900 mm.There should be a clearance of at least 200 mmbetween any part of the lamp and the inside ofthe enclosure.Alternative constructions fordraught-proof enclosures are suitable if it is established that similar test results are obtained.NOTE For production surveillance conditions, a smallerenclosure of 500 mm ×500 mm × 500 mm may be used,providing the internal ambient temperature does not exceed 40°C during temperature measurement, the lamp beingmounted in the centre of the enclosure.
The internal ambient temperature shall be measured with a thermometer screened from directradiation from the test lamp.The thermometer is tobe placed level with the lamp about halfway between the lamp and the wall.
The standard measurement position shall be cap-upunless another burning position is specified for therelevant lamp.The suspension of the lamp shall notaffect the convection around the lamp in any adverse manner.
Test lampholders consisting of a metallic sleevefitted with a thermocouple have been standardizedfor lamps provided with various types of caps.Thevarious test lampholders shall be as specified in therelevant figures.
Each test lampholder shall have a permanentlyattached stranded flexible wire which in the case ofES caps and single contact bayonet caps serves asone of the supply leads.A thermocouple shall bepermanently attached to the lampholder sleeve.(See Sub-clause 7.3.) In addition, a spring wire shallbe used around the outside of the sleeve to assuregood physical contact between the sleeve and thecap of the lamp. Figure 1, page 8, shows the generalconstruction features and assembled position of alampholder for an ES cap. Figure 2, page 9, showssupplementary information.BS 5371 pdf download.