ES235 Datasheet, PDF (14/37 Pages) Cyrustek corporation – 4000 Counts DMM / Peak

ES235
4000 Counts DMM / Peak
1.11. Frequency Counter
The time base of the frequency counter is derived from an external crystal oscillator by
4,000,000
T_counter =
F_osc
Where F_osc is the frequency of the crystal oscillator. Thus, the counter has a 1-second time base
when a 4MHz oscillator is used. The frequency counter can select the proper range automatically or
manually. Auto-range operation extends over six decades, from 400.0Hz to 40.00MHz. The following
table summarizes the Full-Scale range of the frequency counter.
Range
Full Scale
FR1
400.0Hz
FR2
4.000KHz
FR3
40.00KHz
FR4
400.0KHz
FR5
4.000MHz
FR6
40.00MHz
*If input frequency is less than 1.0Hz, ES235 will show 0.0Hz
1.12. Duty Cycle Measurement
When frequency mode is selected, push HZ key to enter duty cycle measurement. The duty cycle
mode range is within 5.0% to 95.0% (< 10kHz@3Vpp). The minimum resolution is 0.1%. If the
source frequency duty cycle is smaller than 5.0%, the UL will be shown on the LCD display. If the
duty cycle is larger than 95.0%, the OL will be shown on the LCD. When the frequency is zero, the
duty cycle display will be 0.0% or “UL” shown.
V 2.2
14
2015/12/15