The acquisition and management of meteorological precipitation data

BS 7843-3.1:1999 pdf free.The acquisition and management of meteorological precipitation data一 Part 3: Specification for raingauges – Section 3.1: Storage raingauges.
Construction of the components of this type of gauge shall be in accordance with the dimensions specified in Figures6, 7, 8, 9 and 10.
The outer can (Figure 7) shall be made either from 127 mm x 1.2 mm seamless drawn copper tube, and 1.2 mm copper sheet, and 0.6 mm diameter brass bar (construction type A) or from 0.7 mm copper sheet (construction type B). The support pins (detail B, Figure 7) shall be soldered or riveted into the outer can at three equally spaced angular positions. The finish on the inside of the outer can shall be natural, grease free and the finish on the outside of the outer can shall be polished and lacquered.
For the inner can (Figure 8) the body shall be made from 1.6 mm thick copper tube, 1143 mm士0.25 mm intermnal diameter. The diaphragm shall be made from 0.6 mm copper sheet. The handle shall be made from 3 mm diameter round brass bar, the base shall be made from 1.6 mm copper sheet and the handle eyes from 2 mm copper sheet. The finish shall benatural, grease free.
For the funnel (Figure 9) the body shall be made from 1.2 mm seamless or brazed updrawn tubing having an internal diameter of 130 mm. The top ring shall be made from brass. The tube shall be made from seamless brass. The funnel shall be made from 0.6 mm copper sheet. The finish inside shall be natural, grease free and on the outside it shall be polished and lacquered.
The funnel shall be checked for ease of fit and correct seating over the top of the outer can. It shall be removable without undue force, but it shall fit firmly to the outer can without rocking.
The inside of the funnel shall be washed with dilute nitric acid by the manufacturer, to remove any grease or flux left behind after manufacture.
The dip rod (Figure 10) shall be made from cedar with the cut edges sealed with varnish. Each full division shall be 24.88 mm apart which represents 2 cm of rain, the engravings shall be 0.4 mm wide, flled black. After final assembly the engraved faces shall be roughened parallel to the scale markings using grade 80 emery cloth.
2.4 The Octapent raingauge Mk. 2a Construction of the components of this type of gauge shall be in accordance with the dimensions specified in Figures 11, 12, 13, 14,15 and 16.
The outer can (Figure 12) shall be made from 0.6 mm thick copper sheet. The finish on the inside of the outer can shall be natural, grease free and the finish on the outside of the outer can shall be polished and lacquered.
For the inner can (Figure 13) the body, base, handle eyes and large tube shall be made from 1.6 mm copper. The handle shall be made from 3 mm diameter round brass bar, the top cone and small tube shall be made from 0.6 mm copper and the side plate from 1 mm copper. The finish shall be natural, grease free.
For the funnel (Figure 14), the body, the funnel and cone shall be made from 0.7 mm copper, with the top ring made from brass and the tube from seamless brass. The finish inside shall be natural, grease free and on the outside it shall be polished and lacquered.
The funnel shall be checked for ease of fit awl correct seating over the top of the outer can. It shall be removable without undue force, but it shall fit firmly to the outer can without rocking. The inside of the fmuiel shall be washed with dilute nitric acid by the manufacturer, to remove any grease or flux left behind after manufacture.
The frost protector (Figure 15) shall be made from 50 mm icL, 5 mm thick ply rubber, with the ring made from 1 mm brass and the plug made from lead. The finish shall be naturaL To assemble the frost protector, slip the brass ring over the tube into its place and force the lead plug into the tube.
The dip rod (Figure 16) shall be made from cedar with the cut edge sealed with varnish. Each full division shall be 10.24 mm apart, this represents 20 mm of rain. The engravings shall be 0.4 mm wide, filled black. Alter final assembly, the engraved faces shall he roughened parallel to the scale markings using grade 80 enmery cloth.
3 Rain measures
3.1 The 10mm rain measure
The details of the widely used 10 mm rain measure are shown in Figure 17.
The 10 nun rain measure shall be manufactured from good quality, clear, soda lime glass not less than 1.5 mm thick, of uniform thickness throughout, well annealed and free from stnalions awl other visible defects.
The dimensions and shape of the mea.smmre shall he as shown in Figure 17. The portion A—W shall be cylindrical, the portion “B—C” shall taper towards the lower end and (he open end shall be splayed and shall have a lip “L”.
The graduation marks shall be fine, clearly etched and pennaiwnt lines of uniform thickness. When the ilteasure is held in a vertical Position with the lip to the left, the centres of the graduation marks shall lie in a vertical line down the front of the measure, and all lines shall be horizontal and evenly spaced.
The measure shall be graduated for 0.1 mm of rainfall from 0.1 mm to 10.5 mm with an additional graduation at 0.05 mm. The whole millimetre graduation lines shall be marked on the back of the measure as well as on the front. The 0.05 mm graduation line shall be extended round the measure. The 1 mm mark shall appear on the parallel section of the body of the measure. Graduations shall be plainly figured, to the right of and immediately opposite the end of the graduation lines. The 0.05 mm graduation extending around the measure shall not be annotated.
11w inseril)tion ‘Gauge diameter 127 nun (5 inches)” shall be marked to the left of the scale.
The inscription “mm” shall be made above the scale between the 10.5 mm graduation mark and the top of the measure.
All graduations, letters and figures shall be not less than 4 rum high an(l filled l)errnment white.
The measure shall contain l26.(8 cm3 of water when filled to the 10 mm graduation mark, the bottom of the nleniscu.s being in the horizontal plane containing the graduation mark.
The maximum error allowed at the 2 mm graduation and at any higher graduation mark shall be ±0.05 nmi of rainfall. The maximum error allowed at any graduation mark below 2 mm is ±0,02 mm of rainfall.
3.2 The 50 mm rain measure
The details of the widely used 50 nun rain measure are shown in FIgure 18.
The 50 mm rain measure shall be manufactured from good quality clear soda or borosilicate glass not less than 1.5 mm thick, of uniform thickness, well annealed and free from siriations and other visible defects.
The dimensions and shape of the measure shall be as shown in Figure 18. The open end shall be splayed and provlde(l with a lip. The measure shall stand vertically on a horizontal surface; if necessary the base shall be ground to achieve this.
The graduation marks shall be fine, clearly etched and permanent lines of uniform thickness. When the measure is placed in a vertical position with the lip to the left, the centres of the graduation marks shall he in a vertical line down the front of the measure. and all lines shall be horizontal and evenly spaced.BS 7843-3.1 pdf free download.The acquisition and management of meteorological precipitation data