What are the reference values you are using to validate the data and generate this warning message?


The limits for RTD increase and RTD decrease are shown in the table below.

 

MAX RTD INCREASE

MAX RTD DECREASE

During Fitment

1

1

During Tyre Inspection or Removal 

0.5

10


 Let us explain the reasons for these various limits.


RTD INCREASE
The RTD of a tire can normally not increase during a given life cycle (i.e. other than re-grooved or retreaded tyres). However in reality, the RTD may be taken in different locations during 2 inspections. If the time period during these 2 inspections is short, it may happen that the technician records a slightly higher RTD.  When a new inspection is made, the previously entered RTD is recorded in the “INSPECTION HISTORY” grid available in the TIRE CARD. If we were to put a tolerance of “0”, it would require the user to cancel the current data entry, then go to TIRE CARD to edit the previous RTD entry and finally return to the FITMENT AND REMOVAL page to enter the new inspection, which can be quite troublesome.
 The reason for the slight tolerance is to avoid such trouble. Toolbox is being used in some Total Tire Management contracts in which thousands of tires are being tracked every day, especially when calculating the PROJECTED LIFE, Toolbox will always use the latest RTD measurement. Therefore such RTD increase would not affect the formula.


RTD DECREASE
 As you can see we have 2 different limits here. When doing an inspection or a removal, the amount of RTD decrease will depend on the duration since the last inspection as well as the wear rate of the tire. We have set a value of 10 as we consider it to be high enough to avoid the warning message to appear too often. On the other hand, when a tire is mounted again on a certain position, the RTD should be the same as when it was last removed. So we are using a tighter criteria here but not using 0 for the reasons explained in the previous section about RTD INCREASE.