Measurement of lifespan in hours is made for stationary engines installed, such as drives for pumps, diesel generators, marine motors, and agricultural machinery. This information is necessary for timely maintenance, repair, replacement of components and assemblies, as well as the write-off of fuel and lubricants. Means changes can be different - from the simple recording of hours worked by the motor in the log or logbook, to complex electronic means of collecting and analyzing statistical information. It should be noted that depending on the method of accounting, morochas may be or may not be equal to the standard hour. There is a task of transfer of hours in a standard astronomical clock for example, to schedule a date for the next oil change.
The easiest way to implement the accounting engine hours for engines operating in stationary mode, i.e. without changing the speed of rotation of the crankshaft. This mode of operation is typical for small plants for electric power generation diesel generators. To ensure a stable frequency generated by the electric current of the generator shaft must rotate with the same speed, with minimal deviations. Under such loads, you can use the simple calculation of the service life - manually record actual working time in the motor magazine or use any electrical or barometric sensor that triggers the clock mechanism during engine operation. Under this system of accounting morochas equal to the usual astronomical hour, and therefore, no recalculation is required.
Much more difficult to take into account the wear of the engine at variable speed of the crankshaft. This situation is typical for marine propulsion. At high speeds increases fuel consumption and increases the friction in the friction pairs of the engine. For counting hours with regard to these variable factors used thematische accounting system. A special mechanism is installed on the output shaft of the motor, for fixing the number of revolutions of the engine. On the basis of this counter planned maintenance work, fuel is deducted. With such a fastening system, to accurately translate the hours to watch will not work, because depending on the mode of operation of the engine per unit time is incident, a different number of hours. Knowing the average engine speed, based on statistical data we can deduce the empirical conversion factor.