Checkline PK2X User Manual
Page 8
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Helpful Hints:
To maximize the life of the battery:
■
Shut the instrument off intermittently in order to allow the battery to recover.
■
Allow the instrument to cool down if the outside temperature is hot.
■
Keep the battery fully charged. Do not allow it to completely drain between
charges.
■
When storing the unit at room temperatures, charge/discharge it once every
three months.
6.0 INFORMATION ON BATTERY MANAGEMENT
Several factors effect the battery life:
■
The warmer the operating environment, the shorter the battery life; the cooler the
environment, the longer the battery life.
■
The more times the battery is completely drained, the shorter the battery life.
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What is the actual rate of the fan? Images 1, 3, 5, 7, and 8 are all “frozen,” so the rate
could be taken as 3,300. 1,100, 825, 660 or 550. Which is correct?
In order to determine the fan’s actual speed, a mark is added to one
of the blades and the test is run again.
Image No.:
1
2
3
4
Flash Rate:
3.300
1,650
1,100
916.6
Image No.:
5
6
7
8
Flash Rate:
825
733.3
660
550
Using the orientation mark, it is now clear that the images appearing at 3,300, 825 and
660 RPM are multiple-image harmonics. In each of these cases, three identification
marks appear. On the other hand, a singular image appears at 1,100 and again at 550.
Here, only one mark appears. Recall that “a singular image always appears at exactly
one half of the object’s true RPM.” 550 is one half of 1, 100. Therefore, the rate of the
fan must be 1,100 RPM.
Example 2: (Within Range No Mark Needed)
This example illustrates how the actual speed of an object can be determined without
the use of an orientation mark—provided that the object has a suitable shape.
Assume that the speed of this cam is known only to be less than
7,000 RPM. Because it has a unique shape, it does not need an
identifying mark. As the flash rate is lowered from 7,000, the
following harmonic images (see page 18) appear.