MEATEST, s.r.o.
M-142 Multifunction Calibrator
User Manual v54
31
Uncertainty calculation of set power
Uncertainty of set power displayed on the Accuracy line of the display is calculated according to the following
formula:
for active power
d P =
( dU
2
+ dI
2
+ dPF
2
+ 0.03
2
) [%]
for reactive power
d P =
( dU
2
+ dI
2
+ dPF*
2
+ 0.03
2
) [%]
for apparent power
d P =
( dU
2
+ dI
2
+ 0.03
2
) [%]
where dP is the uncertainty of set power
[%]
dU is the uncertainty of set voltage
[%]
dI is the uncertainty of set current
[%]
dPF is the uncertainty of set PF (cos
)
[%]
dPF* is the uncertainty of set sin
[%]
Generation of frequency
The multifunction calibrator can generate several different voltage shapes with exact frequency, amplitude and
duty cycle. The output signal is present at BNC coaxial connector FREQ located at the front panel. The signal is
not present at any other output terminal.
There are two frequency generation modes. The first mode (PWM) allows the generation of squarewave output
signal with calibrated amplitude, frequency and duty cycle. Frequency range is up to 10 kHz. The second mode
(HF) also provides squarewave output signal with very steep rising edge, typically less than 3 ns.
PWM mode
Frequency range:
0.1 Hz to 100 kHz
Voltage range:
1 mV to 10 Vpp
Signal shapes:
squarewave, negative PWM NEG – symmetrical PWM SYM – positive
PWM POS
HF mode
Frequency range:
0.1 Hz to 20 MHz
Voltage range:
5 V
pk-pk
0, -10, -20, -30 dB
Signal shapes:
symmetrical squarewave
PWM mode can be used to calibrate the input sensitivity of oscilloscopes at frequencies up to 10 kHz. HF mode
can be used to calibrate the time base of oscilloscopes.
To switch between the modes, keep pressing “F” direct mode button. The display includes the symbols for
currently selected mode (PWM or HF).
Control in the frequency mode
•
Press F direct mode button. The calibrator switches to PWM mode. If HF mode is desired, press F button
once more. The main data on the display is the frequency.
•
The display shows the following data:
*
set frequency
*
relative deviation of frequency
*
signal amplitude (PWM mode ) or attenuation (HF mode)
* duty cycle (PWM mode only)
