ASRB NET Farm Machinery Testing, Evaluation & Standards: practice questions

1 · Types of tests: commercial, batch, confidential and prototype · medium

Which statement correctly contrasts the OECD tractor performance code (Code 2) with the OECD rollover protective structure codes?

1. Code 2 reports measured values without a pass mark; the ROPS codes apply acceptance criteria
2. Code 2 sets a minimum PTO power for each class, while the ROPS codes only report deflections
3. Both apply pass marks, and Code 2 requires SFC below one fixed limit for every tractor size
4. Neither applies criteria; ROPS deflections are just reported for the buyer to judge as wished

2 · Types of tests: commercial, batch, confidential and prototype · medium

A national tractor testing station wants formal recognition that its laboratories are technically competent to produce valid results. The international standard it is accredited to is

1. ISO 9001, quality management systems for any organisation that designs or makes products
2. ISO 14001, environmental management systems for sites that handle fuels and lubricants
3. ISO/IEC 17025, competence of testing and calibration laboratories
4. ISO 4254-1, general safety requirements for agricultural machinery used on the farm

3 · Test codes: OECD, BIS, PAES/PNS, ASABE and ISO · medium

OECD Codes 6 and 7 apply to

1. dynamic and static ROPS testing of standard wide-track wheeled tractors
2. protective structures fitted to track-laying tractors used in forestry
3. front-mounted and rear-mounted ROPS on narrow-track wheeled tractors
4. noise and vibration at the seat of tractors with closed operator cabs

4 · Test codes: OECD, BIS, PAES/PNS, ASABE and ISO · hard

Report X gives a tractor's maximum PTO power measured under a national code; report Y gives another tractor's maximum PTO power under the OECD code. Before comparing the two numbers directly, the main thing to establish is

1. whether both stations used the same make of dynamometer, since makes always read differently
2. whether both tractors carry the same paint and badge, since appearance shows the engine fitted
3. whether both reports were printed in the same year, since older reports always overstate power
4. whether both codes define test conditions alike, as load steps and limits are code-specific

5 · Test codes: OECD, BIS, PAES/PNS, ASABE and ISO · medium

The main reason the OECD tractor codes were set up was to

1. fix a world price for tractors so that importers cannot undercut makers
2. replace all national road-safety rules for tractors with one OECD law
3. license tractor operators through a single international driving test
4. make a test report from one member country recognised in the others

6 · Hydraulic lift test · medium

A gear pump of displacement 18 cm³/rev runs at 2000 rev/min. At the test pressure the measured delivery is 32.4 L/min. The volumetric efficiency is

1. 90 %
2. 180 %
3. 111 %
4. 1.5 %

7 · ROPS and FOPS tests · hard

In the OECD ROPS codes, the energies to be absorbed and the crushing forces are set as functions of the tractor's reference mass. The reason is that

1. a heavier tractor is less likely to overturn, so its structure can be weaker
2. the reference mass sets the size of the cab, which sets the clearance zone
3. a heavier tractor has a larger engine, which must be protected by the ROPS
4. a heavier tractor carries more energy in an overturn and loads its structure more

8 · Tests of sprayers and harvesting equipment · medium

The volume median diameter (VMD, Dv0.5) of a spray is the droplet diameter

1. below which half of all the droplets fall by number
2. of the single largest droplet measured in the spray
3. below which droplets make up half the total spray volume
4. that occurs most often in the measured size spectrum

9 · Interpreting test reports · hard

A test report gives the maximum drawbar power of a tractor on a concrete track as 80 per cent of its maximum PTO power. A researcher wants to estimate drawbar power in tilled soil. The most defensible approach is to

1. use the 80 per cent track ratio unchanged, since it is set by the transmission alone
2. raise the ratio above 80 per cent, since soft soil lets the tyres grip with less slip
3. use the ratio of engine to PTO power, since drawbar losses match transmission losses
4. apply a lower, soil-specific ratio from traction theory or field data