GTC TA300 User manual

User’s Manual
DIESEL ENGINE TACHOMETER
General Technologies Corp.
TA300

Table of contents.
1. Safety Rules Page 1
2. Technical Specifications Page 2
2.1 General specifications Page 2
2.2 Electrical Specifications Page 2
3. Operation Page 3
3.1 Instrument description Page 3
3.2 LCD Display Page 3
3.3 Buttons description and operation Page 4
3.4 Measurement procedures Page 5
3.5 Additional functions Page 6
4. Application information Page 8
4.1 Using the piezoelectric sensor Page 8
4.2 Troubleshooting Page 8
5. Maintenance Page 10
5.1 Battery replacement Page 10
5.2 Cleaning Page 10
6. Warranty Page 10
1. SAFETY RULES
•This instrument is designed for indoor use at temperatures between 32° and 104° F
(0°C and 40°C) and altitudes up to 6500 ft (2,000 meters).
•To ensure that the instrument is used safely, follow all safety and operating instructions
in this operation manual. If the instrument is not used as described in this operation
manual, the safety features of this instrument may be impaired.
•Do not use the instrument if the instrument, the cables or the piezoelectric pickup, or
if you suspect that the instrument is not operating properly.
•When using the instrument, keep away from moving parts (fan, drive belts, etc) and
hot objects (exhaust pipes, muffler , catalytic converter, etc), to avoid personal injuries
and damage to the instrument, the cable or piezoelectric pickup.
•Do not connect or apply more than 42 VDC or any AC current directly to the
connectors or the piezoelectric pickup.
•At all times, to avoid electrical shock, use CAUTION when working with electrical
circuits above 60V DC or 25V AC rms. Such voltages pose a shock hazard.
•Do not operate this instrument without the rubber holster or the battery cover off.
•To avoid electrical shock or damage to the instrument, do not exceed the specified
input limits.
Exceeding the limits listed above when using this apparatus, or not observing
the precautions listed above can expose you to physical injury and permanently
damage your instrument and/or parts and components of the vehicle under test.
‘SmarTach’, ‘V Ready, and ‘GTC’ are trademarks of General Technologies Corp.

2. TECHNICAL SPECIFICATIONS
2.1 General Specifications
Display: LCD 4½ digit main measurement, 2 x 3½ digit for maximum and
minimum measurements, indicators for low battery, number of
cycles and units.
Update rate: 3 per second (for LCD).
Engine system Comp. Fuel injection pump with lines for each cylinder.
Engine cycles: 2 and 4 cycles.
Fuel injection line: Up to 9 mm dia. (Depending on piezoelectric pickup used)
Power: 9 Volt battery, type MN1604.
Auto power off: Automatically powers off after 1 minute of no operation.
Battery life: Approximately. 30 hours. (w/alkaline battery).
Cable length: 6’ (1.8 m)
Dimensions: 6” x 4” x 1.5” (158 x 100 x 37 mm) without cable.
Weight: Approximately. 14 Oz. or 406 g. (Including battery).
Included accessories: Padded hard carrying case, user’s manual, rubber holster and
1 x 9 Volt alkaline battery.
2.2 Electrical Specifications
•The specifications below are typical at 23° C, and will vary slightly from device to device,
and with temperature. The input voltage should not exceed the indicated maximum
values, to prevent personal injury or damage to the instrument.
Page 2
Function Measurement
Range
Accuracy/Repetitivity Input
Characteristics
RPM 100 to 19999 RPM
2 and 4 cycles
Accuracy: 0.1% ± 1 LSD
Input Impedance:
2 MΩminimum +
100 pF (Max).
Input Protection:
± 42 VDC Max.
Sensitivity
Adjust
Signal sensitivity
adjustable from 1 to 10 Default setting: 5
Trigger Level
Adjust
Trigger level adjustable
from 20% to 80%
of peak input signal
Default setting: 50%

Page 3
3. OPERATION
3.1 Instrument Description
1) Protective rubber holster
2) LCD Display
3) Power ON/OFF / Reset button
4) Sensitivity Increase button
5) Number of Cycles button
6) Sensitivity Decrease button
7) Trigger Level Adjust function button
8) Piezoelectric pickup
9) Ground clip
3.2 LCD Display
3.2.1 LCD Display description
Low battery indicator
• This message warns the battery voltage is below the minimum recommended and it
needs to be replaced with a new battery.
• If the battery voltage is low, but still allows for the operation of the instrument, the low
battery indicator will turn and stay on until the battery is replaced with a new one.
Note: If the unit turns off immediately after being turned on, it indicates that battery voltage
is below the absolute minimum, and the battery should be replaced to prevent malfunction.
MAX - Maximum reading
• Holds and displays the maximum value of the measurements, with the last digit rounded to ‘0’.
The maximum measurement is automatically reset when turning the unit off or manually by
momentarily pressing the ‘Power On/Off / Reset’ button.
Fig. 1 - Instrument description
Fig. 2 - LCD Display
MAX
MIN
Cycles
Maximum value
Minimum value
Measurement units
Low battery indicator
Number of cycles
Measurement
Sensitivity
Increase
Sensitivity
Decrease
Trigger Level
Adjust
Number of
Cycles
MAX
MIN
Cycles

Page 4
MIN - Minimum reading
• Holds and displays the minimum value of the measurements, with the last digit rounded
to ‘0’. The minimum value is automatically reset when turning the unit off or manually
by momentarily pressing the ‘Power On/Off / Reset’ button.
Cycles - Number of Cycles
• Displays the selected number of cycles: 2 and 4.
Measurement units
• Displays the measurement unit: RPM
Measurement reading
• Displays the measurement.
3.3 Buttons description and operation
3.3.1 Power ON/OFF and Reset
• When the instrument is OFF, to turn it ON press the ‘Power ON/OFF / Reset’
button until the unit turns on (in approximately 1 second).
• When the instrument is ON, to turn it OFF press and hold the ‘Power ON/OFF
/ Reset’ button until the display turns off (in approximately 3 seconds).
• When the instrument is ON, press momentarily the ‘Power ON/OFF / Reset’
button to reset the Maximum and Minimum values.
Note: To extend battery life, the TA300 will automatically turn off after 1 minute of being
idle (i.e. no button pressed and no input signal). Turning the unit off manually,
when not in use will prolong battery life.
3.3.2 Number of cycles
• Press the ‘Number of Cycles’ button to select the number of cycles for the
engine under measurement. Each time the button is pressed the number of
cycles will change between 2 cycles and 4 cycles. The selected setting will
show on the display.
3.3.3 Trigger Level Adjust
• Press and hold the ‘Trigger Level Adjust’ button to enable the trigger level
(threshold) adjust function. After this button is pressed, the display will show
the current trigger level (50% is the default setting), and the trigger level can
be adjusted by using the ‘Sensitivity Increase’ or ‘Sensitivity Decrease’ buttons
to increase or decrease it.
3.3.4 Sensitivity Increase and Decrease buttons
• The first time the ‘Sensitivity Increase’ button is pressed, the display will show
the sensitivity setting, and each time the button is pressed again it will increase
the signal sensitivity of the TA300. A few seconds after the button is released
the display will resume to show maximum and minimum readings.
• The first time the ‘Sensitivity Decrease’ button is pressed, the display will show
the sensitivity setting, each time the button is pressed again it will decrease the
signal sensitivity of the TA300. A few seconds after the button is released the
display will resume to show maximum and minimum readings.

Page 5
3.4 Measurement Procedures
CAUTION
To avoid personal injuries and damage to the instrument carefully inspect the
fuel injection lines and fuel pump for damage or leaks, and avoid using this
instrument in case any damage or leaks are found. Never touch the
piezoelectric sensor during a test. Wear insulating gloves when working around
high voltage, and hot parts, and keep away from moving parts (fan, drive belts,
etc) and hot objects (exhaust manifold and pipes, muffler, catalytic converter, etc.)
1-Clamp the piezoelectric pickup onto a clean unpainted section of any diesel injection
pipe. Do not over tighten the thumb screw (see Fig. 3)
2-
Clip the alligator ground clip onto a clean unpainted section of the same injection line.
3- Connect the forked terminal to the piezoelectric pickup.
4-Turn the instrument on.
5- If necessary change the number of cycles to match the engine under measurement
by pressing the (Number of cycles) button repeatedly until the display shows the
correct setting.
4- Start the diesel engine.
6- Read the RPM on the display.
Fig. 3 - Piezoelectric sensor and ground clip on fuel line
Fuel injection line
Piezoelectric sensor
Ground clip
Thumb screw

Page 6
3.5 Additional functions
3.5.1 Minimum and Maximum functions
The TA300 holds the maximum and minimum values of the measurement on the display.
• The maximum and minimum values are reset upon turning the TA300 power on,
or by momentarily pressing the (Power On/Off and Reset) button.
• The maximum and minimum values will be shown with the last digit rounded to 0.
3.5.2 Sensitivity Adjust function
The TA300 allows the user to adjust the level of signal sensitivity it can detect, in order to
match a wide variety of fuel pressures and fuel lines characteristics.
To use the Sensitivity Adjust function:
1-Turn the instrument on.
2- To perform adjustments of the signal sensitivity while performing actual measurements,
follow the procedure as described in ‘3.4 Measurement procedures’.
4-The first time the ‘Sensitivity Increase’ or the ‘Sensitivity Decrease’button is pressed,
the display will show the sensitivity setting (see Fig. 4), and each time the button is
pressed again it will increase or decrease the signal sensitivity. A few seconds after
the button is released the display will return to show maximum and minimum readings.
Notes:
• Adjusting the signal sensitivity of the TA300 while performing RPM measurements,
provides quick feedback on how this setting affects the response of the TA300 in any
given situation.
• Signal sensitivity can be adjusted between 1 and 10. The factory calibration val-
ue is 5.
• The lower the value of the sensitivity setting the bigger the signal input needs to be for
detection by the TA300, and converserly higher sensitivity settings can detect smaller
signals input.
• The values set by using the Sensitivity Adjust function are stored in internal memory,
and will be retained even if the instrument is powered off, the battery is depleted or
removed.
Cycles
%
Sensitivity
Threshold
Fig. 4 - Example of display when in Sensitivity or Trigger Level Adjust mode

Page 7
3.5.3 Trigger Level Adjust function
The TA300 also allows the user to adjust the trigger level (threshold) it uses to measure
RPM from the signal it receives from the piezoelectric pickup. This feature can be used
to compensate for excessive noise in the signal generated by vibration, electromagnetic
interference or particular characteristics of fuel pressure, injection patterns and fuel lines.
To use the Sensitivity Adjust function:
1-Turn the instrument on.
2-To perform adjustments of the trigger level while performing actual measurements,
follow the procedure as described in ‘3.4 Measurement procedures’.
3-Press and hold the (Trigger Level Adjust) button until the minimum reading in the
display is replaced by the word ‘Threshold” followed by a set level number and then
a ‘%’ sign (see Fig. 4).
4- While holding the (Trigger Level Adjust) button pressed, use the (Sensitivity
Adjust increase) or (Sensitivity Adjust decrease) buttons to adjust the % value.
Notes:
• Adjusting the trigger level of the TA300 while performing RPM measurements, provides
quick feedback on how this setting affects the response of the TA300 in any given
situation.
• The trigger level can be adjusted between 20% and 80%. The default value for the
trigger level is 50%.
• For example, if the trigger level is set to 70%, the TA300 will register an engine cycle
when the signal level from the piezoelectric pickup reaches or exceeds 70% of the
maximum signal.
• Higher trigger levels increases the noise rejection, and lower trigger level will help in
measuring RPM when dealing with inconsistent injection pulses. For most cases the
default 50% level is the optimal value.
• The values set by using the Trigger Level Adjust function are stored in internal mem-
ory, and will be retained even if the instrument is powered off, the battery is depleted
or is removed.

Page 8
4. APPLICATION INFORMATION
4.1 Using the piezoelectric pickup
Important
The piezoelectric pickup is constructed with an special piezoelectric
ceramic material and it can be easily damaged by impacts or if excessive
pressure is applied.
1-For the piezoelectric pickup to work, it requires that a good electrical connection be
established between the center part of the pickup, and the ground clip. This can be
achieved in two ways:
• Fit the piezoelectric pickup to a clean unpainted section of an injection line. Then
connect the ground clip to that same clean section of the injection line as shown in
Fig. 3. or to a convenient ground in the engine. If necessary scrape and sandpaper
the line in order to expose the metal surface.
• If you do not wish to scrape the fuel line, you could tightly wrap a piece of aluminum
foil around the pipe and clamp the piezoelectric pickup over this foil. Make the foil
wrap long enough to allow placing of the ground clip on the same piece of foil. Use
of aluminum foil will often fix problems due to bad electrical connections between
the piezoelectric pickup and the injection pipe and ground clip.
2- Do not over tighten the clamp. Use of excessive force or tools such as pliers to tighten
the clamp will result in damage to the piezoelectric pickup and void the guarantee.
3-If not already connected, locate the forked terminal at the end of the red wire (near
to the alligator ground clip) and push it under the flat head of the connector pin at the
corner of the piezoelectric pickup. This connector pin is the one with a coil spring. You
will see that this spring presses a conical washer against the flat pin head. The forked
terminal must be inserted between this washer and the flat pin head. Hook up is now
complete.
4.2 Troubleshooting
The main factors that may cause unstable, erroneous or in some cases prevent the TA300
from obtaining a measurement at all are:
• Poor electrical contact between the center of the piezoelectric pickup and the
ground clip.
• Engine/fuel line vibration.
• Weak signal due to the characteristics of the fuel line or the fuel injection pump.
4.2.1 Poor electrical contact
Please refer to ‘4.1 Using the piezoelectric pickup’ for detailed instructions on how to use
the piezoelectirc pickup.
4.2.2 Engine/fuel line vibration
The piezoelectric pickup is specially designed to detect the expansion of the fuel line cause
by the pulses of pressure generated by the fuel when injected into the cylinder. However
under some conditions the vibration of the engine and fuel line may cause an excessive
amount of noise in the signal, in which cases the TA300 may not recognize the signal and
generate incorrect RPM readings or no reading at all.

Possible solutions:
• Use the Trigger Level Adjust function to change the trigger level (threshold) until a
stable RPM is obtained.
• Sometimes the vibration noise may be caused or magnified by the minute ‘jerking’ of
the cable connecting to the piezoelectric pickup to the TA300, and providing some
strain relief may be of help in obtaining RPM readings. To provide strain relief to the
piezoelectric ppickup, attach the red wire (which is connected to the pickup ) to the
same fuel line using electrical tape or a cable tie, as shown in Fig 5.
Page 9
Fig. 5 - Strain relief setup for piezoelectric pickup
Fuel injection line
Piezoelectric pickup
Electrical tape or cable tie
4.2.3 Weak signal due to the characteristics fuel line or fuel injection pump
There are many factors that may contribute to the piezoelectric pickup not being able to
generate a signal (pulse) strong enough for the TA300 to detect. These situations may
cause low, slow or inconsistent built up of fuel pressure in the fuel line. Some common
causes are listed below:
• Leaky, dirty or damaged fuel injectors.
• Damaged fuel pump.
• Very low cylinder pressure.
• Presence of air in the fuel line.
Possible solutions:
• Change the position of the piezoelectric pickup in the fuel line.
• Place of the piezoelectric pickup to a different fuel line.
• Change the signal sensitivity of the TA300 using the Sensitivity Adjust function (refer
to section ‘3.5.2 Sensitivity Adjust function’ for detailed instructions) until a reading is
obtained. If the RPM readings are erroneous or unstable proceed to adjust the trigger
level (refer to section ‘3.5.3 Trigger Level Adjust function’ for detailed instructions)
until a stable RPM is obtained..

5. MAINTENANCE
12
3
Fig 6 - Battery replacement
Page 10
5.1 Battery replacement
1-Release the rubber holster from plastic enclosure by pulling from the bottom of the
holster as shown in the illustration (Fig. 6).
2-Push the rubber holster forward until the battery compartment cover is exposed.
3-Slide open battery cover located at the back of the unit.
4-Connect the new battery observing the polarity of the battery connectors.
5-Replace battery cover and rubber holster.
4-Press the ‘Power On/Off / Reset’ button on the TA300 until the display turns on. If
the display does not turn on, check the battery polarity and reinstall if necessary.
5-To turn the unit off, press and hold the ‘Power On/Off / Reset’ button again the
displays turn off.
5.2 Cleaning
Keep the instrument in its carrying case when not in use and do not subject it to dampness
or severe heat or cold. Do not use the instrument in the rain, if it should accidentally get
wet, dry it off with a clean paper towel before storing it away.
Protect the unit from contact with any solvents. Never clean with a solvent or petroleum
based medium such as gasoline, as these chemicals may attack the plastic parts and
cause permanent damage. Never use an abrasive cleaner. Cleaning should be limited to
wiping with a clean damp paper towel and a small amount of soap if required. Dry the unit
thoroughly after any cleaning.
The unit is a sealed instrument and contains no user serviceable parts other than the bat-
tery, which can be replaced by opening the drawer on the back of the unit. Opening other
parts of the unit will void the warranty.
6. WARRANTY
With the exception of the battery, this instrument is warranted against defects of material or
workmanship which develop within a period of one (1) year following the date of purchase
by the original owner. For details see Standard Warranty Information on our web page at
www.gtc.ca or you may request a printed copy.

Part # TA300EMN1804EN
© 2010-2017 General Technologies Corp.
Printed in Canada
#121 - 7350 72nd Street Tel: [phone]
Delta, BC Fax: [phone]
Canada V4G 1H9 email: [email protected]
“SmarTach” and “GTC” are trademarks of General Technologies Corp.
To visit our website, scan the QR code below with your smart phone.
Or type this URL in your browser:
www.gtc.ca