Operation – Sealey DBG5010 User Manual

Page 2

5. OPERATION

5.1. Setting up (The dial ball gauge is a comparator not a measuring tool)

5.1.1. Measure the bore diameter or gap to be measured to the nearest millimetre with a rule or vernier callipers. The bore or gap

must range between 50mm and 160mm nominally with this tool. (up to 164.5 with spacers)

5.1.2. select the range of parts required, anvils, spacers and 50mm distance piece using the table on the last page.

5.1.3. Assemble the dial bore gauge with selected parts as shown in fig.1, fig.2 and fig.3. Ensure all components are clean and when

assembled are finger and thumb tight; no tools are to be used.

5.1.4. Insert the dial stylus into the probe body as shown in fig.4. The stylus will meet with resistance internally and the dial pointer will

begin to rotate clockwise. one complete cycle of the pointer is recommended for registration and will be indicated by the secondary dial

indicator annotated 1-5. The small pointer should now be indicating "1" [one].

5.1.5. Clamp the dial stem with the thumb screw.

DO NOT overtighten.

5.2. Calibration

5.2.1. depending upon accuracy requirement, calibration can be achieved with slip gauges, micrometer or vernier callipers. In our instructions

example the micrometer is suggested, which has similar accuracy to the dial gauge.

5.2.2. set the micrometer (50mm-75mm) to the target size "x", for example Ø63.50 and lock. In our example the tolerance required is H9 from

Bs 4500:1969 (+.074/-0).

5.2.3. From instruction 5.1.2 and the tables on the back page; parts required are the anvil 60 plus spacer ring 30 or 40, from item 5 in fig.1.

Assemble as shown above.

5.2.4. Maneouvre the gauge anvil and nib inside the measuring gap of the micrometer (fig.11). This activity could be eased by assistance or

carefully clamping the micrometer with toolmakers clamps on to an angle plate.

5.2.5. observe the large dial pointer movement. It is essential that the axis of the gauge anvil and spring loaded nib are centralised in the

micrometer measuring faces. It is essential to observe the total sweep of the dial pointer using the small dial. remember from the initial

setting the pointer had rotated one full cycle.

5.2.6. When satisfied with alignment, hold the position and rotate the dial bezel until the "0" [zero] aligns with the pointer. lock the bezel with

the thumb screw. Your dial bore gauge has now been calibrated for use in a Ø63.00 to Ø64.00 bore ie +/-0.5mm of target.

5.2.7. The tolerance band can now be set using the two "markers" on the bezel. our example states the tolerance band to be +0.074 to -0. set

one marker opposite and in line with "0" [zero] (fig.6) and the other +7.4 (fig.7) divisions apart. note! the larger the deflection the smaller

the bore.

nib

Anvil

Without spacer

(1mm)

(2mm)

(3mm)

(4mm)

use the spacer rings to achieve "x" = 51,52,53,54,56 etc..

spacer ring for

intermediate sizes

distance

piece

(50mm)

Insert the stylus for 1 full large pointer revolution

fig.5

fig.4

fig.3

fig.2

fig.1

small pointer on "1"

Pass

Fail

Tolerance markers

fig.6

fig.7

Example for reference only

Bezel clamping screw.

Please note the

tolerance markers will

not pass the screw when

clamped.

dBG5010 Issue: 1 - 08/04/14

Original Language Version

Be aware, nib projection is 2mm.

Aim for 0.5mm to 1.5mm as the

measurement zone.

With spacer

With spacer and distance piece