OPERATING INSTRUCTIONS MODEL DT-31K1
KEYBOARD CONFIGURATION
POWER
ON
DIGATRON MODEL DT-31
TACH / CHT
MODE
RECALL
MAXIMUM
STORE
POWER OFF
SET LIMITS
CLEAR
MEMORY
RECALL
POWER ON
When turned on, your instrument will begin a 10 second
display test. At the end of the test, your instrument’s serial
number will be displayed.
To bypass this test press the
MODE
button.
SETTING FUNCTION LIMITS
Before using your DT-31K1, be sure to set the operating
limits for each sensor.
The instrument will not allow limits to
be set while the engine is running
. This is to prevent
possible damage to your instrument.
Limits allow the instrument to give you a visual warning if
any of the inputs exceed their limit.
Limits should be set at
levels that allow you to react to the visual warning before
engine damage occurs.
You will also need to set a calibration
number so the instrument can display the correct RPM.
To set the limits, the instrument must be turned on and the
kart’s engine turned off. Press and hold the
MAXIMUM
RECALL
and
MEMORY RECALL
buttons simultaneously
until the display flashes. This will put the instrument into the
Set Limits mode of operation, which is indicated by the
display flashing. To increase the limit, press the
MAXIMUM
RECALL
button. To decrease the limit, press the
MEMORY
RECALL
button. To increase or decrease the limit by a large
amount, press and hold either the
MAXIMUM RECALL
or
the
MEMORY RECALL
button until the approximate limit
value is reached. When finished setting the tach limit, press
the
MODE
button to set the next limit. Repeat the above
procedure to set the remaining limits. Set limits at levels high
enough for normal operation, but not so high that engine
damage can occur before you can respond to a problem.
The tach limit requires the setting of two separate
parameters. The first is the maximum RPM for safe engine
operation. The second number is for tach calibration. In order
to display the correct RPM for different engine types, the
instrument divides the tach input signal by the tach
calibration number. This number can be between .5 and 31.
Select this number so that it will provide the correct display
for your application using the
MAXIMUM RECALL
and
MEMORY RECALL
buttons.
The most frequently used numbers are:
.5 - for some single cylinder 4 cycle motors
1 - for single cylinder 2 cycle and some 4 cycle motors
2 - for 2 cylinder 2 cycle and 4 cylinder 4 cycle motors
If you are unsure of the exact tach calibration number for
your engine, experiment. If your calibration number is
currently set at 1 and the RPM displayed is double what it
should be, set the calibration number to 2. Alternately, if the
RPM displayed is half of the correct value, decrease the
calibration number to half of the current number.
To save the current limits and exit the Set Limits mode, press
the
STORE
button or switch.
CYLINDER HEAD TEMPERATURE
Cylinder head temperatures (CHT) usually run in the 300
º
F to
475
º
F range. The best way to determine the correct
temperature for your particular motor is to tune for proper
plug or piston color and then observe what the head
temperature is for various throttle settings and atmospheric
conditions.
Temperatures of 450
º
F or over will damage the standard CHT
sensor. If your motor frequently runs at cylinder head
temperatures over 450
º
F your instrument should have an
exhaust gas temperature function, which can use a
thermocouple CHT sensor. This sensor can be used without
damage at higher temperatures, but it is not as accurate as
our standard CHT sensor.
TACHOMETER
The tach displays RPM in thousands of RPM.
For example, if your display shows 9.50, your RPM is 9500
RPM.
MODE BUTTON
During operation, the
MODE
button is used to change from
the primary to the secondary function in the display. When
the instrument is first turned on, the primary function (tach)
is displayed. The secondary function (CHT) operates in the
background until the
MODE
button is pressed, or until it’s
limit is exceeded.
STORING DATA
The
STORE
button or the optional
REMOTE STORE
switch can be pressed up to three different times to store the
current values of each function into memory. The displays
and the optional
WARNING INDICATOR LIGHT
will flash
to indicate a successful store of information. After three sets
of numbers are stored, additional attempts to store
information will be ignored. In addition, the instrument
automatically stores a maximum value for each sensor during
the current recording period.
