V-TEK PT-55, User Manual

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68 PT-55 User’s Guide
Recommended Maintenance D291308.6r.fm
Recommended Maintenance
V-TEK recommends recalibrating the PT-55 every six months. The PT-55 laptop should be
backed up periodically. No further maintenance is required.
As with any computer system, V-TEK, Inc. recommends users create a
computer
Recovery Disk prior to operation and conduct periodic back-
ups as needed. Visit the computer manufacturer’s website for instruc-
tions on creating a recovery disk. V-TEK, Inc. does not create or main-
tain recovery information for the PT-55 laptop. Creating a recovery disk
is solely the users’ responsibility.
If any problems are encountered while using the PT-55, contact your V-TEK service representa-
tive, referring to the Customer Service Contact sheet located at the back of this manual.
Speed Calibration
No advance speed calibration is necessary. Advance speeds are microprocessor controlled.
Accuracy & Calibration
The expected accuracy of the PT-55 is +/- 3.0 grams of the full scale value of the load cell. The
load cell range is 0-200 grams.
It must be noted that a number of factors can affect the accuracy of the system and cause the
readings to differ from the factory calibrated values. Something as simple as how level the place-
ment surface is may have an effect. Also, such things as rough handling of the load cell may
have an effect. The load cell is a very sensitive device.
Note: Never pull on the chain by hand. Exceeding the cell’s rated force can shift its output
or even destroy it.
The PT-55 should arrive in good usable condition and provide an accurate and linear result. If the
output values are slightly different than achieved at the factory, this should not be of concern.
Tape peel forces are cyclic in nature, as evidenced by actual tests performed. A few grams differ-
ence is inconsequential as long as the system is linear and tracks properly. However, if maximum
accuracy is desired, it will be achieved by calibrating the PT-55 in the exact position that it is
going to be used in.
Table 1: Load Cell Tolerances in Grams
Weight Low Range High Range
200 197 203
100 97 103
50 47 53
20 17 23
10 7 13