# How to Choose Single-Ended or Differential Voltage Measurement (Single-Ended Focus) – 8501035

## Examining Important Aspects of Voltage Measurement

Voltage is a difference in electric potential between two points, and a measure of force for current flow in a conductor or circuit. You can choose to measure voltage single-ended, or you can measure voltage differentially. This whitepaper is part 2 of two in the series, How to Choose Between Single-Ended or Differential Voltage Measurement. It is recommended that you also read part 2 of the series, which focuses on differential voltage.

In this part, we consider single-ended voltage measurement. How you measure voltage is important; because voltage measurement is at the heart of most of your processes that monitor current, temperature, resistance, and strain. Thus, your method of measurement should be well-matched to your application to positively impact your results and avoid error.

### Single-Ended Input Voltage Measurement

A single-ended input measures the potential of one point with respect to a fixed common reference; such as a signal return or a reference voltage offset from signal return. Its chief differentiator is two input connections with one of variable potential and one of a fixed potential. If the single-ended input has multiple channels; then each channel measures one potential with respect to signal return, or a common fixed reference.

#### Some Applications of Single-Ended or Return-Referenced Measurement

• Commonly used to measure an output voltage where one connection is already tied to a fixed common reference potential or return. Not applicable in multi-channel applications where; output potentials may be offset or independent of one another, do not share a common reference, or where output voltages are connected in series.
• Mostly preferred where the input signals have higher level full-scale spans greater than 1V, due to poor noise rejection.
• Most applicable for taking measurements over short distances, generally less than 3 meters.
• Often chosen where it’s necessary to accommodate many channels in a small space, thus less wiring, simpler.
• Typically used where the emphasis is on lower cost because less connectors and wiring are required; or higher channel density.
• Not recommended where the output to input coupling is made in a noisy environment with high EMI and RFI; or where the coupling cable is not shielded.