Mechanical or Solid State Switch Closure

1.2.2

TIME Measurement (Cont'd)

The time interval between events can be examined when these events are represented by mechanical

or solid state switch closure. This is especially valuable in determining the time for mechanical

phenomena such as contact closures or certain process controls. Additional versatility is provided

when measurements are made using these input signals in that the counter does not reset

automatically at the end of the process. Unless reset is initiated manually or remotely, the counter will

sum the time for consecutive intervals.

Pulse Inputs

When the time interval to be measured is represented by discrete pulses, it is frequently desirable to

have separate start and stop command inputs. A trigger from one sensor can be used to start the

count and a trigger from a different sensor can be used to stop the count. Consecutive pulses on a

single line may also be accommodated.

Time Increment

The proper selection of time increment depends to a great extent upon a particular application. When

the period under investigation is of long duration, short time increments may tend to overflow the

capacity of the counter. The CF-604 provides for time increments of 10, 100, 1000 microseconds and

10 milliseconds and the time increment should be chosen for maximum resolution without exceeding

the capacity of the display.

It is advisable in precision measurements of time interval to examine the input waveform prior to

taking measurements in order to optimize the techniques used.

Time for "N" Events

The presence of a variable selector greatly extends the utility of the time measurement counter. Any

number of periods (within the range of the switch settings) may be counted in order to provide greater

accuracy. This same technique may be applied to the measurement of time interval between events.

When multiple events are surveyed, the expression is titled, "Time for N events". The time for N

events function is useful in the nuclear field and other similar applications where it is necessary to

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