DS 19 OPERATION No. DS 00 : Revolution counters and pressure gauges.. Op. DS 00
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TOOLS
7 REVOLUTION COUNTERS
Certain adjustments and checking cannot be carried out effectively without the use of a revolution counter.
In order that these adjustments and checks shall be accurate, it is necessary to use an instrument which is sufficiently
accurate for this work. In particular the instrument should be accurate to within 20 r.p.m. at 600 r.p.m.
Electric Revolution Counters
The following instruments have been tested by us with satisfactory results :
"RABOTTI" sold by Société FENWICK, 15, rue Fénelon, Paris, 10e, under number 2436-T.
"SOURIAU, type 1094" sold by Société SOURIAU, 9, rue du Général-Gallieni, Billancourt (Seine).
"L.T.I. type CT1" sold by Société LE TRANSISTOR INDUSTRIEL, 1, rue Anatole-France, Puteaux (Seine).
"GUYOT ELECTRONIC" sold by Société R.E.M., 44, rue Brunel, Paris, 17e.
"SPEED-O-METER JUNIOR", sold by Société C.I.D., 71, rue Chauveau, Neuilly-sur-Seine (Seine).
The electric revolution counters should be periodically checked (approximately every month). This operation can
be carried out by means of a stroboscopic disc, MR-4142-20 (see Pl. 80A).
Mechanical Revolution Counters
These mechanical revolution counters are sold by Société FENWICK, under number 2434-T.
It is preferable to use this revolution counter on a test bench with an appropriate coupling (contact breakers,
dynamo, injection pump, speedometer etc.).
This instrument can also be used on the car, by comparison with an electric revolution counter with a curve which
is known.
In order to carry out this operation, the pulleys and belts should be in good condition, the pulleys should be in
correct alignment and the belts tensioned correctly (see Op. DS 231-0).
These conditions are also imperative in order to use the instrument when carrying out adjustments on the car.
Stroboscopic Disc
This instrument can easily be made. For constructional dimensions ask for note MR-4142-20 from Service
"Méthodes Réparations", 11 bis, rue de la Source, Paris, 16e.
Fit the disc on the high pressure pump pulley and fit the light in position as indicated on Pl. 80A.
The pulleys and belts should be in good condition, the pulleys in correct alignment and the belts correctly tensioned
(see Op. DS 231-0).
a) Checking on the car :
We particularly recommend this instrument in order to check the output of the high pressure pump
(see Op. DS 391-0). In effect the precision of this is greater than that of the better tachometers (it does not
depend on the current frequency).