1、BRITISH STANDARD BS 6978-1: 1988 ISO 7256-1: 1984 Seed drills Part 1: Methods of test for single seed drills ISO title: Sowing equipment Test methods Part1: Single seed drills (precision drills) UDC 631.331.5:620.1:001.4BS6978-1:1988 This British Standard, having been prepared under the directionof
2、the Agricultural Machinery and Implements Standards Committee, was published under the authority ofthe Board of BSIand comes into effect on 29 July1988 BSI 04-2000 The following BSI references relate to the work on this standard: Committee reference AGE/27 Draft for comment 82/78599 DC ISBN 0 580 16
3、708 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Agricultural Machinery and Implements Standards Committee (AGE/-) to Technical Committee AGE/27, upon which the following bodies were represented: AFRC Institute of Engineering Resear
4、ch Agricultural and Allied Workers National Trade Group Agricultural Engineers Association British Agrochemicals Association Ltd. Health and Safety Executive Imperial College of Science and Technology Long Ashton Research Station Ministry of Agriculture, Fisheries and Food National Farmers Union Coo
5、pted members Amendments issued since publication Amd. No. Date of issue CommentsBS6978-1:1988 BSI 04-2000 i Contents Page Committees responsible Inside front cover National foreword ii 0 Introduction 1 1 Scope and field of application 1 2 Reference 1 3 Definitions 1 4 General test conditions 1 5 Man
6、datory tests 2 6 Test results 4 7 Test report 5 Annex A Performance of bench tests 6 Annex B Device for measuring the depth of sowing 7 Annex C Frequency Test no 8 Annex D Frequency histogram 9 Annex E Optional tests 10 Annex F Example of test report on precision drills 12 Figure 7 Table 1 6 Table 2
7、 8 Table 3 Sowing unit no.1 14 Publication referred to Inside back coverBS6978-1:1988 ii BSI 04-2000 National foreword This Part of BS6978 has been prepared under the direction of the Agricultural Machinery and Implements Standards Committee. It is identical with ISO7256-1:1984 “Sowing equipment Tes
8、t methods Part1: Single seed drills (precision drills)”, published by the International Organization for Standardization (ISO). Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology
9、and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “part
10、 of ISO7256” appear, referring to this standard, they should be read as “Part of BS6978”. Cross-reference. ISO7424, to which reference is made in the text for information only, has been withdrawn. A British Standard does not purport to include all the necessary provisions of a contract. Users of Bri
11、tish Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to14, an inside back cover and a back cove
12、r. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS6978-1:1988 BSI 04-2000 1 0 Introduction The aim of this part of ISO7256 is to make available to test offices and other intereste
13、d organizations a standardized test method permitting reproducibility of tests when they are carried out in geographically remote areas and/or in different climatic conditions; the main objective being comparability for any one model of equipment. This condition of reproducibility limits the number
14、of mandatory tests which can be used and eliminates mandatory tests in the field. However, these tests may be carried out optionally at the instigation of the test office or at the request of the manufacturer. 1 Scope and field of application This part of ISO7256 specifies test methods for single se
15、ed drills (precision drills). 2 Reference ISO7424, Agricultural equipment Matching of wheeled tractors and rear mounted implements Code numbering system. NOTEA future International Standard will deal with classification and terminology of equipment for sowing and planting. 3 Definitions For the purp
16、ose of this part of ISO7256 the following definitions apply. 3.1 single seed drills (precision drills) drills whose metering mechanism distributes seeds singly by means of a burying device at predetermined intervals to form a sowing line NOTEAs the great majority of sowing equipment has equidistant
17、spacings, the tests refer only to this type of equipment. 3.2 sowing unit (for seed) unit generally comprising the metering mechanism and the burying device 3.3 metering mechanism (for seed) mechanism which takes seeds from a batch leaving the hopper individually or in groups and deposits them in a
18、line (or row) 3.4 burying device device generally comprising a coulter, a device to regulate the ground penetration depth of the coulter and a unit that covers the seed 3.5 coulter device for opening a furrow in the ground in which the seeds leaving the metering mechanism are placed 3.6 flow rate am
19、ount of seed distributed, expressed as a number, mass or volume of seed per unit of time 1) 3.7 application rate amount of seed distributed, expressed as a number, mass or volume of seed per unit of length or surface 1) 3.8 spacing the distance between two successive seeds in the row theoretical spa
20、cing spacing set on the control mechanism and stated by the manufacturer 3.9 miss for a single seed drill, the absence of a seed where there should be one theoretically. In practice, by analogy with statistical evaluation of results, all spaces larger than1,5 times the theoretical seed spacing are c
21、onsidered to be misses (see6.1.1) 3.10 multiples for a single seed drill, the presence of two seeds or more where there should only be one. In practice, by analogy with statistical evaluation of results, all spacings less than0,5 times the theoretical seed spacing are considered to be multiples (see
22、6.1.1) 4 General test conditions 4.1 Seed drill 4.1.1 Selection The seed drill to undergo testing may be selected by the representative of the test office in agreement with the manufacturer. 1) For precision drills, only the number is to be taken into consideration for flow rate and application rate
23、 measurements.BS6978-1:1988 2 BSI 04-2000 The seed drill shall, in all respects, conform strictly to the specifications, which the manufacturer is required to send to the test office in writing. The test report (see Annex F) shall specify how the drill to be tested was chosen. 4.1.2 Manufacturers in
24、structions Use the drill in accordance with the manufacturers instructions, which shall specify, among other things a) the maximum forward speed and, if appropriate, the minimum forward speed, expressed in metres per second; b) the maximum, and if appropriate, the minimum number of revolutions, expr
25、essed in minutes to the power of minus one (min 1 ), and/or peripheral speed, expressed in metres per second, of the metering mechanism; c) the species and types of seed which may be sown; d) the metering mechanisms suited to each seed species. 4.1.3 Checking of specifications The technical characte
26、ristics supplied by the manufacturer shall be indicated in the test report and shall be checked. 4.2 Seed 4.2.1 Types The tests shall be carried out taking into account the manufacturers specifications. 4.2.1.1 Single-purpose drill If the seed drill is stated to be specifically for one or more types
27、 of seed and/or distribution methods, the test shall be carried out exclusively with the seeds indicated by the manufacturer, and, as appropriate, of the size specified. 4.2.1.2 Multipurpose drill If the drill is stated to be multipurpose, the tests shall be carried out with the following four types
28、 of seed: type a: a medium size round seed3 0,75mm in diameter (for example, pea or a coated seed the coating of which shall be smooth and of a regular shape); type b: a small seed of regular shape (for example, cabbage) of diameter less than3mm; type c: a large irregular seed (for example, bean or
29、flat maize seeds) of diameter greater than6mm; type d: the most difficult seed permitted by the manufacturer (for example unpelleted genetically monogerm beet seed, carrot, etc.). NOTEThe seeds shall not have been subjected to any treatment which could change their physical properties, except that i
30、ncorporated in the coatings. 4.2.2 Characteristics The dimensional characteristics (scale and granulometric profile), purity (percentage of foreign bodies, bad seeds and broken seeds) and water content of the batch of seeds used shall be noted in the test report. 4.3 Ambient conditions The hygrometr
31、ic levels shall be observed and noted in the test report. 5 Mandatory tests 2) 5.1 Nature of test (seeAnnex A) The mandatory tests deal essentially with the precision of seed planting and the efficiency of metering. Each test shall be carried out with three different units, either three units on one
32、 multirow drill or three independent sowing units if each one has a metering mechanism. Tests1,2,3 and6 (seeAnnex A) shall be carried out with the sowing unit either static or mobile. Test4 (seeAnnex A) shall be carried out with the sowing unit mobile. Test5 (seeAnnex A) shall be carried out with th
33、e sowing unit moving over a bed of sand. 5.1.1 Static tests With the sowing unit stationary, the metering mechanism shall be driven at a rotary speed equal to that which it would have for actual work, i.e.taking into account the theoretical forward speed and the adjustment of the ratio between the m
34、etering mechanism and the driving wheel speeds. In order to simulate the relative movement of the drill above the ground, an adhesive strip moving at the relative forward speed of the drill when travelling without slipping may be run underneath the seed drill. NOTEThis recording on to an adhesive st
35、rip may be replaced by any other recording method, such as an acoustic or optical method. The method used shall be noted in the test report. 5.1.2 Mobile test The sowing unit shall be fixed to a mobile trolley moving at a constant speed and without jolting over a stationary adhesive strip. 2) For op
36、tional tests see Annex E.BS6978-1:1988 BSI 04-2000 3 NOTERecording by means of an adhesive strip may be replaced by any other recording method, such as an acoustic or optical method. The method used shall be noted in the test report. 5.1.3 Test on a bed of sand The sowing unit shall move over a bed
37、of sand of specified characteristics (see the note) at a constant speed and without jolting. The coulter shall penetrate this sand to a depth at least equal to the minimum working depth. For this test, the coulter may be equipped with deflectors which, without interfering with the placing of the see
38、ds, prevent the sand from falling back. It shall be maintained at a constant depth. The forward speed shall be equal to the actual speed of the seed drill at work. NOTECharacteristics of the sand may be as follows: a) foundry sand: granulometry of85 to1204m, clay content intended to provide a bindin
39、g agent (20 to25%), water content between4 and6%; b) a pure sand (such as Fontainebleau sand to which a low-viscosity oil is added in the proportion of1%). 5.2 Adjustments and procedure 5.2.1 Position of the coulters (seeAnnex A) Tests1,2 and6 (seeAnnex A) may be carried out with the coulters raised
40、, on the recommendation of the manufacturer. The distance between the metering mechanism seed outlet and the impact surface shall be as close as possible to that in actual practice between the seed outlet and the bottom of the furrow. Test3 (seeAnnex A) shall be carried out partially with the coulte
41、r in position so as to check whether there is any seed rebound against the coulter wings. If so, the distance between the metering mechanism outlet and the impact surface shall be slightly greater, but still as close as possible to the actual distance so as not to extend the seed fall distance undul
42、y. This distance shall be noted in the test report. Tests4 and5 (seeAnnex A) shall be carried out with the coulter in position. 5.2.2 Filling the hoppers The hoppers shall be filled at the time of the test, avoiding any abnormal compaction of the seed. For the tests with the hopper full, half full a
43、nd one eighth full, these volumes correspond to100,50 and12,5% of the total volume of the hopper plus the usable volume of the metering mechanism feed chamber. 5.2.3 Forward speed Three relative drill/ground speeds shall be chosen corresponding to the forward speeds from the range1;1,50;2;2,50 and3m
44、/s in accordance with the manufacturers instructions. For static tests, if the driving wheel is mounted on tyres, the rotary speed is given by the equation where v is the relative forward speed; R is the radius of the tyre under average load. 5.2.4 Adjustment of the metering The tests shall be carri
45、ed out with the average spacings currently used in agriculture for these types of seeds. These metering amounts shall be recorded in the test report. 5.2.5 Speed adjustment of the metering mechanism As the seed spacing control is obtained by a combination of the number of the holes or cells of the m
46、etering mechanism and its rotary (or linear) speed, the tests shall be carried out at maximum and minimum speeds and at the intermediate speed closest to the mean arithmetical speed between the maximum and minimum speeds specified by the manufacturer for the type of seed to be tested, adjusting the
47、metering member (drum, disc or belt) on the sowing unit for the particular spacings. If there is only one means of adjusting the spacing, the test shall only be carried out with this one setting. 5.2.6 Slope test The slope tests shall be as follows: a) ascending a slope: incline the sowing unit11 to
48、wards the rear (corresponding to a20% slope); b) descending a slope: incline the sowing unit11 towards the front; c) slope to the right: incline the sowing unit11 to the right; d) slope to the left: incline the sowing unit11 to the left. 5.2.7 Duration of the tests The number of runs may vary accord
49、ing to the length of the test bench. They shall cover a total workable distance corresponding to a minimum of250 seeds in situ. For each run on the test bench (mobile test) or each run on a mobile strip (static test), disregard an appropriate length to cancel out irregularities resulting from initial acceleration.BS6978-1:1988 4 BSI 04-2000 Before each test for which the hopper is filled, rotate the metering mechanism sufficiently to allow the seed flow to fill the feed chamber of the distributing mechanism. 5.2.8 Measuring procedu
