IMS 3638 Manual Del Usario página 17

Run-up Time Setting
This setting defines the amount of time it should take for RPM levels to stablise at a constant
speed before starting a measurement. This parameter may be designated by national standards
or regulations.
1) Press OK to select this parameter.
2) Use to scroll through the number of seconds: from 0 to 6 (usually '2').
3) Press OK to confirm the selection and proceed to the next parameter.
Measurement Time Setting
To define the length of time a measurement sequence should last, set the time as follows:
1) Press OK to select this parameter.
2) Use to scroll through the number of seconds: from 5 to 15 (usually '7').
3) Press OK to confirm your selection and proceed to the next parameter.
External Tachometer Setting
Type 3638 has a built-in acoustic RPM meter, which computes the number of revolutions
directly from the acoustic signal by a progressive FFT and envelope analysis. Vehicle measure-
ments can, therefore, be accomplished comparatively faster and more comfortably than most
other modes of measurement. Press OK to continue configuration of other parameter settings.
However, in some cases where the exhaust noise level is low compared to other sources, such
as vehicles with noisy (rear) engines, the normal acoustic detection of RPM using Type 3638 A/
B's internal RPM meter is not suitable. It is, in these cases, recommended to use an external
tachometer. Type 3638 A/B's preferred external tachometer is Brüel & Kjær's Tachometer Type
2979. Other tachometers that are compatible include those from Cartec and Maha. To select the
type of external tachometer, do the following:
1) Press OK to select the parameter.
2) Use to scroll through the compatible RPM meters available: Type 2979 (default),
Cartec or Maha.
3) Press OK to confirm your selection and proceed to the next parameter.
Compressed Air Measurement Setting
Measurement of compressed air applies only to lorries and is mandatory in some countries. The
measurement procedure is described in detail in EU directive 70/157/EEC, regulation 51. To set
Type 3638 A/B to to measure compressed air, do the following:
1) Press OK to select the parameter.
2) Use to scroll between On and Off commands.
3) Press OK to confirm your selection and proceed to the next parameter.
PART 1
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