Sturtevant Richmont 10191, Руководство пользователя

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than tester), the offset can be used to avoid having to build an exact model of the joint
(using the joint simulator and filter) to obtain identical results. As long as the actual joint
remains the same (no new components or design changes to existing components) and the
test results are in the 50 - 56 inch-pound range, the tool is producing good assemblies.
The advantages of this approach include less test model design time up front, ease of use in
practice, and rapid test execution (effective zero time to configure joint simulator). If the
offset is known for each tool/joint configuration, testing is extremely rapid. This is of par-
ticular importance when there are large quantities of tools to be tested.
The disadvantages of this approach are that one must be careful to assure the correct offset
is obtained for each joint/tool configuration, and recorded for use in determining whether
tool performance has changed. Somewhere in the tool record the "Filter 4, Joint Q offset =
-8 inch-pounds" must be recorded and used during torque testing. Also, if the tool is to be
used on joint "R" instead of joint "Q", then testing will have to be performed to determine
the correct filter to be used (most consistent results) and the correct offset for that joint/tool
combination.
In many respects, the correlative approach is simplest to use.
The tool-specific approach is somewhat more cumbersome, but yields results which are
very closely aligned with the actual torque which will be experienced on the line. In this
approach, each power tool/joint combination has an individual model of the joint built. The
model consists of an almost exact replication of the specific joint built from two compo-
nents: the joint simulator and a filter selected on the tester itself.
There are two advantages to this approach. The first advantage is that the numbers obtained
from joint audits closely match those obtained from the power tool testing. This is comfort-
ing to those who are uncomfortable with the concept of offsets. The second advantage is
that there can be no arithmetic error in determining whether or not the tool is conforming to
requirements. No calculation of offset means no arithmetic calculation, hence no possibility
of arithmetic error.
There are some significant disadvantages to this approach. The time investment required to
build an exact simulator/filter model of every joint/tool combination in the facility can be
quite large. This information must be recorded, then used for each test of each power tool.
This means the person calibrating the tool must rebuild that exact model each and every
time the power tool is tested. This results in higher ongoing time and labor costs for cali-
bration, and is still not 100% effective. Joint simulators using Belleville washers can be
made to closely emulate almost any joint in their usable range (capacity). But above a cer-
tain torque level, it is necessary to use springs instead of Belleville washers because of heat
buildup in the washer stack during rapid torque application with the power tool. Since it is
almost impossible to obtain a spring for every joint rate experienced in a plant, those plants
using higher torques (above about 300 inch-pounds) are forced to use a correlative approach
above the torque level where washer use is impracticable. If the plant is using torques