what do u understand about "one pulse per revolution"?

Answer 1

*The MRES field specifies the number of pulses per revolution for the stepper motor, while ERES specifies the encoder pulses per revolution.
ERES: Encoder Pulses per Revolution .
MRES: Motor Pulses per Revolution .
*http://www.patentstorm.us/patents/6451228-description.html
*Please read below:
*1 - Principle of the fixed time base tachometer:
The tachometer totals the number of pulses received during a fixed period of time known as the time base. At the end of this period, a value for the frequency measured is shown on the display.
The time base can be set at the time of installation. It is calculated from the formula shown below, where :
B :is the time base being calculated,
Nd : is the number of pulses per revolution,
Nt : is the number of revolutions per minute, and
V : is the value that will appear on the display.
The time base is given by :

B=[V*60]/[Nt*Nd]

Once the time base has been calculated, it is set by means of DIP switches (or changeover switches) situated on the unit.
As an example:
Assume a sensor emits 8 pulses per revolution. What you want to see on the display is a speed in revs per minute. The maximum this speed can be is 2000 rpm.
Nd = 8
Nt = 2000
V = Nt (since what you want displayed is a speed in rpm).
B=[2000*60]/[2000*8]
B=7.5 SECONDS.
Fixed time base tachometers are useful for high speeds but, if the accuracy obtained is to be good, it is essential for the number of pulses per revolution to be high.
To overcome this drawback, Crouzet Automation can supply reciprocal tachometers. These need only a single pulse per revolution and are able to measure both high and low speeds.

Answer 2

Some electric meters produce one data "pulse" for every revolution of the disk. Using meter constants and the duration of time you are able to compute the electrical kW demand and kWh usage.

Answer 3

when a rotating emf (electromagnetic force) producer (motors, as the above stated meters, magnetic coils...) turns exactly one time, there will be produced one pulse (threashhold breaking spike in voltage).