Capelec CAP8500 User manual

PRO01489
Rev B
1130, rue des Marels
34 000 MONTPELLIER France
Tél : [phone]
Fax : [phone]
e-mail :[e-mail]
www.capelec.fr
USER MANUAL
CAP8500
Tachometer petrol & diesel
for gas analysers and smokemeters

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2
CONTENTS
I. DESCRIPTION 3
I.1 FOREWORD 3
I.2 OPERATING PRINCIPLE 3
I.3 GENERAL PRESENTATION 4
I.4 KEY 5
I.5 TECHNICAL CHARACTERISTICS 5
I.6 LIST OF KIT CONTENTS 6
I.7 OPTIONS 6
II. HOW TO USE THE CAP8500 7
II.1 CONNECTING THE TACHOMETER 7
II.1.1 CONNECTING THE CAP8500 TO THE EQUIPMENT 7
II.1.2 CONNECTING THE CAP8500 TO THE VEHICLE 7
II.2 MEASURING THE ENGINE SPEED 8
II.3 TROUBLESHOOTING 9

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I. DESCRIPTION
I.1 Foreword
Thank you for purchasing the CAP8500 tachometer kit for smokemeters and
gas analysers. The ultra-modern design of this product incorporates state of the art
hardware and software technology to address your main concerns: fast installation,
accuracy, reliability and stability.
This tachometer can be used to measure the speed of an engine with no
need to connect an induction clip or piezoelectric sensor, since measurements are
made directly on the basis of the voltage across the vehicle's battery terminals. This
type of measurement is suitable for all types of petrol and diesel engines, and in
most cases, you do not even have to open the bonnet. You can measure the engine
speed simply by plugging the unit into the cigar lighter.
This manual explains how to use the CAP8500 kit, and how to plug it into
your pollution checking equipment. Be sure to read this manual carefully before using
the unit, so as to take full advantage of it. Keep the manual in a safe place for future
reference.
Note:
CAPELEC reserves the right to alter the information published in this
document without notice.
CAPELEC will accept no responsibility for any direct or indirect damage
caused by any means whatsoever, nor for any losses or expense resulting from
misuse of the device.
I.2 Operating principle
The tachometer operates by analysing noise frequencies at the battery
terminals. Certain peripheral devices in the vehicle, such as the alternator, have a
direct effect on the voltage across the battery terminals. When the engine is running,
this voltage does not remain perfectly steady. When studied more closely, one sees
that the battery voltage oscillates slightly in proportion to the engine speed.
By analysing these disturbances, the CAP8500 is able to calculate the
engine speed and transmit it to your pollution checking equipment as an analog or
digital signal.
The CAP8500 can be connected to the CAP3000 smokemeter, to CAP3100
and CAP3110 gas analysers, and to most measuring devices already fitted with a
tachometer function based on an induction clip, piezoelectric sensor or a TTL or
RS232 input.

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I.3 General presentation

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I.4 Key
(1) – Your gas analyser, smokemeter or diagnostics equipment.
(2) – Direct cable connection for the tachometer on your piezo or TTL input.
(3) – Your equipment's induction clip for engine speed measurements on
petrol engines
(4) – Loop simulating a petrol engine ignition harness.
(5) - Light:
Lit steadily = Power on.
Initialisation in progress
Flashing = Measurement in progress.
(6) – Selector for number of cylinders in engine.
(7) – Cable for measurements and power to the unit from the cigar lighter
socket.
(8) - Cable for measurements and power to the unit from the battery.
(9) -Engine speed displayed directly on your analyser's display.
I.5 Technical characteristics
⇒Unit
* Weight: 385 g
* Dimensions: 144 x 98 x
40 mm
* Power cable length:4 m
⇒Power supply
* Power supply: +9 to
+15 VDC
* Consumption: <
500mA
* Inverted connection
protection
⇒Climate conditions
* Service temperature
range: +0 to +45 °C

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* Humidity: 30 % to 90
%
* Storage temperature
range: -32 °C to +55 °C
⇒Measurement characteristics
* Automatic initialisation
* Measurement range:
400 – 9,999 rpm
* Maximum error: <20
rpm at speeds below
2,000 rpm
<2 % in other cases
* Response time: <1
second
* Measurement update
rate: 10 times per second
* Initialisation time: <17
seconds
I.6 List of kit contents
* The CAP8500 unit.
* One battery connection cable.
* One cigar lighter connection cable.
* One user manual.
* One storage case.
I.7 Options
* External power and measurement adapter for 24 Volt HGV
batteries.
* Computer connection cable (RS232 serial port).
* Direct connection cable between the tachometer unit and the
piezoelectric sensor input or TTL input on the measuring equipment.
This cable will be specific to each type of gas analyser or
smokemeter. Contact CAPELEC for a list of available cables.

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II. HOW TO USE THE CAP8500
II.1 Connecting the tachometer
II.1.1 Connecting the CAP8500 to the equipment
There are two different ways to connect the CAP8500 to your equipment:
With an inductive pickup ( 3 ):
If your equipment has a tachometer function, and is fitted with an induction
clip, simply connect this to the loop ( 4 ). Electrical impulses proportional to
the engine speed run through this loop. This lets you simulate the ignition
harness of a four-stroke engine (one impulse every two revolutions).
NB.: this solution cannot be used on a smokemeter since there is
no induction clip.
With a dedicated cable ( 2 ):
Check that the cable you have exactly matches the model of
smokemetermeter or gas analyser that you use. If in doubt, contact
CAPELEC.
- Connect one end to the CAP8500's OUTPUT connector.
- Connect the other end to the tachometer input on your
equipment. The tachometer input is the one to which either the
induction clip or the piezoelectric sensor is connected.
II.1.2 Connecting the CAP8500 to the vehicle
There are two different ways to connect the CAP8500 to the vehicle:
Connected to the cigar lighter
This is the simplest solution. It lets you measure the engine speed with no
need to open the vehicle bonnet. On some vehicles, however, the engine
speed measurement may be less accurate than with the unit connected
directly to the battery.
Connect the cable ( 7 ) to the INPUT socket on the CAP8500. Remove the
cigar lighter from its socket on the dashboard and insert the CAP8500 cigar
lighter plug instead.
Connected to the battery
Connect the cable ( 8 ) to the INPUT socket on the CAP8500 and use the
clips to connect it to the battery terminals, taking care not to invert the
polarity.

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NOTE:
The CAP8500 is connected to the vehicle's DC power supply for two
reasons – to power the unit and to perform the engine speed
measurements. It is therefore essential to connect the unit to the battery
on the vehicle being tested, and not to a spare battery.
When the unit is switched on, the LED ( 5 ) should light up and begin
flashing. If the LED does not light up, check that the contact is switched on,
and check the connection.
II.2 Measuring the engine speed
Once the tachometer has been properly connected, use the selector knob
( 6 ) on the CAP8500 to set the engine type. The position of this selector will depend
on the type of engine (2-stroke or 4-stroke) and on the number of cylinders.
E.g.: For a twin cylinder two-stroke engine, the position of the selector will be
the same as for a four cylinder four-stroke engine.
The CAP8500 will detect the engine speed automatically. The unit will search
for a steady speed each time it is switched on, or if the engine speed falls or the
engine type is setting changed. This phase may last several seconds. During this
time, the LED ( 5 ) will flash slowly and the reading on the display will show 0 rpm.
Once the engine speed has been detected, spot readings will appear directly
on the gas analyser or smokemeter ( 9 ). 10 measurements are sent to the
equipment every second.
YES
NO
YES
YES
NO
NO
Power on
Determination of
steady speed
Time: < 17 seconds
LED light: On steady
Value displayed: 0 rpm
Steady speed
detected
Speed monitoring
LED:
flashing, proportional
to speed
Value displayed:
measured speed
Nomber of
cylinders
changed
Drop in
engine
speed

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II.3 Troubleshooting
On some vehicles, measurements may be inconsistent. There can
be several causes for this. In the event of a problem (unstable or imprecise
readings), minimise the risk of error as follows:
- The battery should be slightly discharged. Better results will
be obtained if the headlights are left on for a few minutes before
starting the motor. It can also be recommended to add any other
continuous electrical load like the rear window unfreezer during the
measurement and before to connect the instrument on the vehicle.
- During the measurement procedure, switch on the headlights to
boost power consumption.
- If measurements were made from the cigar lighter, try measuring
directly on the battery.
If, after initialisation, the tickover speed is stable, but incorrect
(e.g. double the actual speed), change the cylinder number setting until the
correct value appears.