Maintenance – General Technologies TA105 Laser Tachometer User Manual

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4.3.2 TOT (Total revolutions) function

• Apply a reflective mark or a piece of reflective tape to the

rotating object under measurement.

• Slide the function switch to the “TOT” position
• Press the measurement button and aim the light beam to the

reflective mark or tape on the rotating object.

• Verify that the “On Target Indicator“ appears on the display,

indicating that the instrument is detecting the rotation of the

object and the reflective mark on it.

• Proceed to read the total revolutions on the digital display.

4.3.3 Reflective marks

• Cut a 1/2” length of the reflective tape provided, peel off the

back to expose the adhesive, and attach it to the rotating part

or shaft to measure, observing the following recommendations:

- The non-reflective area must always be smaller that the

reflective piece of tape.

- If the object or shaft to measure is reflective, it must first be

covered with a black tape or painted black before attaching

the reflective tape.

- Before applying the tape ensure that the surface is clean

and smooth

4.3.4 Very low RPM measurements

The response time will vary with the rotational speed being

measured. Therefore when measuring very slow rotating parts, it

may be advantageous to follow the procedure below to increase

the update rate of the measurement:

• Depending on the size of the rotating object or shaft,

attach multiples reflective marks, evenly spaced along its

circumference.

• Proceed to measure RPM as described in 4.3.1, and divide the

reading by the number of reflective marks, in order to obtain the

correct RPM.

4.4 Other Functions

4.4.1 Display Hold

• The instrument will automatically hold the last reading

immediately after the “On Target Indicator” on the display

turns off, and hold it while the “Measurement button” is pressed.

4.4.2 MEM function

In every measuring cycle (pressing the measuring button,

obtaining a reading, and then releasing the button), the instrument

will automatically store in its internal memory the Maximum,

Minimum and Last value. To retrieve the values in memory follow

the procedure described below:
• With the instrument off press and hold down the “MEM” button

to display the Maximum value stored in memory. Display

screens will alternate between “UP” (maximum) and the stored

maximum reading. Note the value and release the “MEM”

button.

• Pressing and holding again the “MEM” button will display the

Minimum value stored in memory. Display screens will alternate

between “dn” (minimum) and the stored minimum reading. Note

the value and release the “MEM” button.

• Pressing and holding again the “MEM” button will display

the last reading value stored in memory. Display screens

will alternate between “LA” (Last reading) and the stored last

reading value. Note the value and release the “MEM” button.

This memory retrieval cycle will keep repeating in the order

detailed above.
Notes: The values stored in memory will be retained until a new

measurement cycle is performed.

Removing the batteries, or low batteries will cause all

values stored in memory to be erased.

5. MAINTENANCE

5.1 Battery Replacement

•

When the battery is low and needs to be replaced, the “Low Bat-
tery Warning” symbol will appear on the lower left hand side of
the display.

•

To replace the battery, remove the screw and open the battery
compartment cover (located at the back of the unit), and remove
the battery.

•

Replace with 4 x 1.5 V type AA/UM3 or equivalent observing the
proper polarity of each battery as indicated at the bottom of the
battery compartment.

•

Close the battery cover, and replace the screw.

5.2 Cleaning

5.2.1 Lens cleaning

Debris or dirt on the lens may cause obstruction and impede the

working of the tachometer. If this occurs, either wipe the lens with

a Q-tip (moistened with water only) or blow off the loose particles

with clean compressed air. Do not use solvent on the lenses, as it
may become damage.

5.2.2 Exterior cleaning

Periodically wipe the case with a soft damp cloth and mild household
cleanser. Do not use abrasives or solvents. Ensure that no water gets
inside the instrument to prevent possible shorts and damage.

6. WARRANTY

One year limited warranty, excluding batteries and fuses. For
details see Standard Warranty Information on our web page or you
may request a printed copy.

General Technologies Corp.

#121 - 7350 72nd Street Tel.: (604) 952-6699

Delta, BC

Fax: (604) 952-6690

Canada V4G 1H9