It’s enough for engineer when the waveform captured by oscilloscope occupy 2 divisions of the display area. They don’t think it’s necessary to zoom the waveform to a full screen size. And it’s wrong actually. Today we’ll see why we need to put the waveform at full size of the screen.
The difference between 2 division and full screen display is that the waveform would be “extended”. This cause the change of vertical scale value, which influence the accuracy of vertical measurement. The relation between 8-bits ADC and vertical measurement appears mostly important.
Take the ruler for example, if you take 1m ruler to measure 1.6cm object, it will be 2cm at result. And if you use 10cm ruler, it will come to 1.6cm. This is to say, the smaller the measure unit, the more accurate it is.
So, how does the change of vertical scale value influence the accuracy of measurement?
1. Influence from vertical resolution
The normal digital oscilloscope in the market integrates 8-bits ADC. Every
waveforms are reunited by 256 units of “0” and “1”. We assume that 8 divisions
are the full scale at vertical side, and the quantification level at 256. While the
vertical scale is 500mV/div, the vertical precision will be (500mV x
8)/256=15.625mV. For the same signal, when the vertical scale switch to
50mV/div, that is (50mV x 8)/256=1.5625mV. The vertical precision reaches
1.5625mV.
To make the measurement accurate, you can follow the tip:
Make the measured signal occupy around 6 div of the display screen. Like when you measure a 7Vpp Peak-Peak value sine waveform, the vertical scale should set at 1V/div instead of 2V/div or 5V/div. Furthermore, the voltage resolution is also involved in. Like when it’s on 1V/div voltage, the resolution will be 1V/25=40mV. When it is at 10V/div, the resolution will be 10V/25=400mV. It can be seen that at 1V/div, the resolution will be higher and the value more accurate.
This is also why OWON produce 12 and 14 bits oscilloscope. When using the high vertical resolution oscilloscope, engineers shall not worry for the mistake causing from signal reunite. 12-bits XDS oscilloscope is 16 times clearer against 8-bits one. That is 4096 units of “0” and “1” to reunite a waveform. Even more in XDS2000 series with 14-bits resolution and 16384 units to reunite the waveform. Not only will it makes your vision more clear, but also keep the measured value accurate. That is what OWON keeps doing – makes your best need.
Related Technical Article
- 【実機展示開始】実機展示が東洋計測器ランド本店でスタート
- 【キャンペーン】OWON社スペアナ購入で「EMI対策用近傍界プローブ、RFケーブル」をもれなくプレゼント
- 国際 カーエレクトロニクス技術展2024 に出展
- OWON SDS1000シリーズオシロスコープと定番超入門書の特別コラボレーション
- 【教育現場必見】1台4役!万能計測器がすごい | OWON FDS1102
- OWON、東京ハムフェアで最新スペアナ技術を披露!好評を博す
- ハムフェア2023に出展決定!実機体験でお得なクーポンも進呈!
- OWONとPINTECHが戦略提携協議を締結し、計測機器市場で新たな展開を目指す
- 【機種選定楽々簡単!】計測器検査.COMで体験してください
- 2023年3月末まで年度末納期確約キャンペーン