digital caliper is a precision tool that can be used to accurately determine
the dimensions of most objects. As with any precision instrument, proper
usage and care is very important. Following the suggestions below will
maximize the user’s satisfaction with the caliper, increasing the accuracy
of the measurement and lengthening the useful life of the tool.
Do not operate a digital caliper near any strong magnetic field. Never apply
voltage (e.g. engraving with an electric pen) on any part of this caliper
for fear of damaging the circuit
Before using the caliper, unlock the top thumbscrew and clean the jaws by
sliding your finger over both surfaces of the jaws. Pay special attention to
the jaw tips. Dirt, grease, and small particles tend to accumulate here.
This will make sure that nothing affects the setting of the zero position.
After cleaning, close the jaws together and then press the Zero Button to
set the zero point.
When measuring round stock (bars), don’t rotate the piece in the jaws while
applying pressure. Open the jaws, rotate the bar, and then close the jaws to
make your measurement. This technique will preserve the flatness of the jaw
Use the thickest part of the jaws to make your measurement whenever
possible. Using the knife-edged jaw tips repeatedly (which are thin) will
cause excessive wear on this area over time. The thick, flat areas also
provide a positive “feel” when measuring an object. This will help eliminate
any “tilt” between the jaws and the work piece that can cause an error in
Don’t ever use a caliper as a ‘prying’ tool. Be careful not to drop your
caliper onto a hard surface, which could easily result in bent jaw tips.
Bent tips prevent accurate measurements by interfering with the complete
closure of the jaws. Don’t lay a caliper on your machining equipment (when
running) where it can fall onto the floor. Instead make your measurement at
a bench or desk nearby.
Do not remove or tamper with any part of a digital caliper other than the
battery cover and battery.
Digital calipers are becoming more and more popular due to the ease of
operation, multifunction and high resolution.
They are simple to read. The upper right hand corner displays either ‘mm’ or
‘in’ depending on which read mode has been selected.
When in ‘inches’ mode the far left number before the decimal point is whole
inches. The first number to the right of the decimal is ‘tenths of inches.
The second number to the right of the decimal is ‘hundredths’ of inches. The
third number to the right of the decimal is ‘thousandths’ of inches. A
fourth number (a small 5) will pop up when the slide is between thousandths
indicating 5 tenths of thousandths (or a half of thousandths). Typically the
display is read as thousandths to keep things simple. The display in this
picture would read as 732 thousandths.
If the small 5 is displayed it would simply read 732½ thousandths.
When in ‘mm’ mode the number(s) to the left of the decimal point are
whole millimeters. The first number to the right of the decimal is
‘tenths of millimeters. The second number to the right of the decimal is
‘hundredths’ of millimeters. The display in the picture would read 18.61
Function Buttons –
Pressing the ON button once will cause the display to turn on. Also,
just sliding the scale will activate the display. Once it is ‘on’,
pressing the ON button again will zero the value regardless of the
position of the slide. From that reference point any movement will
display the difference: sliding to the left will display a negative
value and sliding to the right will display a positive figure. This
feature makes it convenient to make comparison between two measurements.
The ‘mm/inch’ button toggles between metric and inch display. Note that
when a caliper is turned on it will always display in whatever mode it
was in before it was turned off.
Most calipers do not have a HOLD button. But if they do, pressing the
HOLD button will ‘freeze’ the display and will show a constant value
regardless of any movement on the slide of the caliper. If the caliper
should be turned off (with the display ‘frozen’) that same value will
display when turned back on. It will remain at that value until the hold
button is pressed again to toggle the hold feature off. Note that if the
caliper is turned off (when in the hold mode) it must be turned on again
using the ON button. Just sliding the scale will not activate the
The HOLD feature is handy for freezing the display when the surrounding
light conditions are poor or there’s a blind spot prohibiting a read. In
that case you can make a measurement, press HOLD, and not worry about
moving the slide (which would change the value) as you bring it into
better light to read the display.
The OFF button simply turns the display off. Also, the caliper will turn
off automatically after a period of no activity to save battery life.
A note on Replacing the Battery:
The battery will need replacing if the display blinks off and on every
second or does not show anything. Follow the procedure below.
Step 1: Remove the battery cover by pressing down slightly with your
thumb and slide the cover away from the display.
Step 2: Remove the old battery.
Step 3: Install a new battery with the “+” side up. Slide the cover back
to the closed position.
Note: If the display is not working properly after the new battery is
installed, remove the new battery and wait 45 seconds to reinstall the
battery again. It may be necessary to repeat this process a couple of
times. The caliper must be completely drained of power before a proper
initialization can occur. (Note: This procedure can also correct a
caliper that is not counting or shows other problems. Try removing and
replacing the battery using this technique before contacting Chicago
Brand for repair.)