ADCMT 7461A - Frequency Measurement (FREQ)

7451A/7461A/7461P Digital Multimeter Operation Manual
7.1.6 Frequency Measurement (FREQ)
7-14
Additional error depending on the AC filter Integration time: 10 PLC
Additional error depending on the integration time AC filter: SLOW
Maximum allowable applied current
Between mA and COM terminals
3A (DC or ACrms)
Input protection By using the 3.15 A/250 V fast blow fuse which is compliant with
IEC60127-2 sheet1
The fuse can be changed on the rear panel.
7.1.6 Frequency Measurement (FREQ)
• 7451A, 7461A, 7461P
Measurement method Reciprocal
Input signal voltage range 100 mVrms to 700 Vrms (However, the input signal is restricted to the
maximum allowable applied voltage.)
Frequency bandwidth
Additional error (% of reading)
Response time *1
20 Hz - 45 Hz 45 Hz - 100Hz 100 Hz - 1 kHz More than 1 kHz
SLOW 20 Hz - 5 kHz 0 0 0 0 3 s
MED 20 Hz - 5 kHz 0.7 0.23 0.04 0 500 ms
FAST 300 Hz - 5 kHz - - 0.1 0 100 ms
*1 Time until the measurement value reaches within 0.1% of the final value in the same range
Integration time Additional error(digit)
100 s  IT < 200 s - In a 3 1/2-digit display 2
200 s  IT  2 ms Includes FAST1 and FAST2. In a 4 1/2-digit display 10
2.01 ms < IT < 9.99 ms - In a 5 1/2-digit display 20
10 ms < IT < 1 PLC - In a 5 1/2-digit display 20
1 PLC  IT < 10 PLC - In a 5 1/2-digit display 20
10 PLC < IT  10 s - In a 5 1/2-digit display 2
Measurement frequency range
Measurement accuracy
(Sinusoidal wave)
1 Hz - 10 Hz 0.05% of reading
10 Hz - 300 kHz 0.02% of reading