SuperFlow AutoDyn, Руководство оператора

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AutoDyn
Operators Manual
Section 6 - Page 22
CH6 AutoDyn Operation.fm
• To use this sensor, select channel 86 (OptTac) as a “1”. Set channel 85 and 87 to “0”.
It also requires a “ratio” setting in channel 94 (RpmRat).
If using the harmonic balancer on the engine or any other rotating device attached directly to the
crankshaft, then the direct readout from the optical tach will be in engine revolutions per second.
Thus, simply set channel 94 to 1.000.
However, when using a pulley on the engine that is running at a different ratio than crankshaft
speed, you will need to enter that ratio into channel 94. Channel 94 is used with Channel 59
(OptRpm) to convert the optical tach frequency from pulley revolutions per second to engine
revolutions per minute.
If you are using the rear wheel assembly on a vehicle, you will need to figure or estimate the
correct ratio between the wheel and the engine. Several channels are provided for calculating that
ratio: Channels 79, 80, and 81 are specification channels used to calculate an overall ratio in
channel 55. If you have entered the correct ratios, then simply enter the OvrRat from channel 55
into specification channel 94, RpmRat. Or, if you know the overall ratio for the gear you are testing
in, simply enter it into any one of the drivetrain ratio channels and leave the other two set to 1.000
to obtain the overall ratio. Channel 94 is then used with Channel 59 to convert the optical tach
frequency from revolutions per second to revolutions per minute.
If you are attempting to obtain engine speed from the wheel or driveshaft, keep in mind, this
method will not work with vehicles equipped with an automatic transmission. Nor can you obtain
an accurate RPM reading if you change transmission gears during the test if you are using the
wheel or driveshaft for obtaining your optical tach reading.
The ENG_SPD test profile provides an easy and automatic way of calculating the channel
94 value. Run the test and follow the instructions. We suggest that once the correct value is
determined, save a Specification file for that vehicle to expedite setup for future tests.
As with the ignition pickups, there are some issues associated with using the optical tach pickups:
• When mounted close (less than 12 inches) to the reflective tape, the signal will
sometimes increase (randomly) by a factor of ~10 (2500 now equals 25000). We don't
know why, but this has become apparent when using the device for engine speed off
pulleys or harmonic balancers on an engine. To alleviate the problem, aim the sensor
so it hits the reflective surface at a tangent line instead of directly (90 degrees) at the
reflective tape. Or, move the sensor farther away from the reflective surface.
• The above problem may also be related to the vibration issue noted below, where
mounting the sensor on a surface off the vehicle or dyno solves the problem.
Unfortunately, when using it for engine speed inside the engine compartment, that
becomes impossible to do.
• When using the device on the engine pulleys or harmonic balancer, the line of sight to
the reflective surface must not become impaired when the engine moves under
torque. It may take several positioning alignments to get the reflective surface to stay
in line when the engine is under load vice simply idling.
• Use the GREEN LEMO 1200A-2448-1 cable and the channel 11 port on the
interconnect panel, not the YELLOW LEMO, channel 12.