Checkline TI-MINIMAX - Manual (Page 68)

Dakota Ultrasonics
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8.4 Calibration / Zero bars & Triple Sided Glass Block
Historically a set of 3” & 6” mild steel calibration bars, or a triple sided glass block
have been used for performing a probe zero. These bars/block are generally
measured and certified to a specific set of standards in a professional calibration
lab, and the corresponding length, velocity, and temperature coefficient are
documented. Dakota Ultrasonics carries a custom set of cal bars and an optical
glass block that are measured and calibrated according to national standards.
The primary advantage of using these bars/block versus setting a standard bolt
aside, as explained in the previous section, is the possibility of losing the stand
alone bolt. Because the factory 3” & 6” bars and glass block are calibrated with
documentation, these can be interchanged between units and cal bars/blocks.
While the 3” & 6” bars provide two specific points to demonstrate linearity, the
triple sided glass block has a third reference point. The glass block has a 1”, 2”,
& 3” reference. Generally the user will set up the two -point calibration on the 1”
& 3” sides first, and use the 2” side for additional verification purposes. This
section explains the procedure for using the factory calibration bars and glass
block as a means of probe zeroing the MINI-MAX.
The first step is to setup a group to document our probe zero data. By doing this,
all the values and settings will be saved to the cell location for easy recall at a
later time. This will allow the user to easily verify the zero value and make any
necessary changes to the MINI-MAX, by adjusting the zero value or temperature
depending on the circumstances or conditions.
Creating a Group Name to Document Probe Zero Data
Note: Select a name that references this group to Probe Zero Data.
1) Press the MENU key once to activate the menu items tab. Press the
MENU key multiple times to tab right, and the ESC key multiple times to
tab left, until the DATA menu is highlighted and displaying the submenu
items.