Operation; Measurement Units - Chauvin Arnoux C.A 1725 Notice D'utilisation

The duty cycle is given by :
t
1
Duty =
t + t
1 2
t
1
or, in %. Duty % = x 100
t + t
1 2
Here, we have :
3
Duty % = x 100 = 60%
3 + 2
To make this measurement with the C.A 1725 or C.A 1727 tachometer, you must:
1) Check the amplitude of the input signal to the device. This serves to determine what threshold
must be set. Here, the amplitude is greater than +1.1 V, so contacts 1 and 3 of the FRB
connector must not be interconnected.
2) Switch the tachometer on by setting the rotary switch to "%".
3) The display unit indicates directly the result mentioned above.
If there is no reading on the display unit, check that the amplitude of the signal to be measured is above
the triggering threshold.

4.1 MEASUREMENT UNITS

The table below indicates the display capacity for each function.
Function
tr/mn or RPM
m/mn (K = 0.1)
ft/mn (K = 0.328)
Hz
Period (ms)
Duty cycle %
Counter
In a measurement extended to 0.1Hz using the Ext input, the minimum values are divided by 10.
On/Off function:
If this function is not overridden when the device is switched on (see below), the device is switched
off automatically if one of the following has not occurred during the last 5 minutes:
- Press of a key,
- Or change of setting of the rotary switch,
- Or interrogation of the digital output.
Before switching off automatically, the tachometer emits an audible beep.

4. OPERATION

Display
60.000 to 99999
6.0000 to 99999
19.680 to 99999
1.0000 to 9999.9
0.1000 to 999.99
0.1 to 99.9
0 to 99999
40