ICAR AICE-JRF/SRF Farm Machinery Testing, Evaluation & Standards: practice questions

1 · 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

2 · 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

3 · 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

4 · Drawbar performance test · medium

With no drawbar load a tractor advances 4.2 m per revolution of its driving wheels. Under a heavy load it advances 3.6 m per revolution. The wheel slip is

1. 16.7 %
2. 85.7 %
3. 6.0 %
4. 14.3 %

5 · 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 %

6 · Noise at the operator's ear · medium

Three independent sources produce 84, 87 and 90 dB(A) at the driver's position. The combined level is

1. 87.0 dB(A)
2. 90.0 dB(A)
3. 261.0 dB(A)
4. 92.4 dB(A)

7 · ROPS and FOPS tests · medium

During a static ROPS test, which observation alone is enough for the structure to fail?

1. The structure bends permanently by a visible amount after loading
2. The paint on the structure cracks and flakes at the welded joints
3. The structure takes more than one minute to reach the required energy
4. Any part of the structure enters the operator's clearance zone during loading

8 · 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

9 · Laboratory and field tests of tillage and sowing equipment · medium

A 3-bottom mouldboard plough, each bottom 30 cm wide, works at 18 cm depth with a measured draft of 12 kN. Its specific draft is

1. 22.2 N/cm²
2. 0.741 N/cm²
3. 133 N/cm²
4. 7.41 N/cm²

10 · Interpreting test reports · medium

Two tractor test reports give specific fuel consumption: tractor A 245 g/kWh at maximum power, tractor B 265 g/kWh at 50 per cent load. Before concluding that A is more efficient, the reader should

1. compare both at the same load, since SFC rises as the load falls
2. convert both to L/h, since g/kWh cannot be compared between tractors
3. add 20 g/kWh to A, since maximum-power runs are always over-corrected
4. ignore load, since SFC depends only on the engine's rated speed