Club of bologna proceedings

3.2 Working performance 
Working performance has been improved 
since the start of the National test. Some 
examples of improved tractor performance are 
detailed below (
Table 9
). 
Elasticity
- Engine elasticity is an 
important performance parameter of 
diesel engines used in agriculture or 
other industries, which operate under 
severe load change conditions. It is 
defined by the following equation, as 
the ability of the engine not to stall 
even if the revolutions go down 
when the load is abruptly increased:
 
 
Max. torque Revol. at max. power 
Elasticity=
________________________________ 
X__________________________________ 

Torque at max. power Revol. at max. torque 
 
Figure 1
shows the changes in the elasticity 
of Diesel engines mounted on tested tractors. 
The average figure for 10 years in the 1970s 
was 1.78, while the average figure for the past 

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Fig. 2 
- Diesel engines: specific fuel consumption in direct and indirect injection 
Fig. 3
- Diesel engines: exhaust smoke concentration 
131 

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Fig. 4
- Noise at the driver's ear 
 
 
 
Fig. 5
- Ambient noise level 
Table 1
Objectives of the official testing
142 

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133
Eliminating poor-quality products 
Guiding appropriate choice and use 
Supporting development and improvement 
Facilitating the trade both domestically and abroad 
Securing labor safety and hygiene 
Promoting environment conservation and energy saving