Why is signal conditioning needed

In fact, some frequencies — like those found in a Hrz AC power lines — can cause unwanted noise in the signal. This is where filtering is used to eliminate those unwanted frequencies for a clean and consistent signal. Excitation: Excitation voltage is required for the operation of an active sensor such as a thermistor, an RTD, or a pressure sensor. The stability and accuracy of the excitation signal directly affects the stability and accuracy of the sensor. Cold-Junction Compensation: Cold-junction Compensation CJC is used for thermocouples — and is required to ensure accurate measurements.

CJC adjusts the thermocouple signal for fluctuations in room temperature and improves measurement accuracy. Signal conditioning is an essential aspect of any data acquisition system and there are many different types of signal conditioners — differing based on both the physical value that they measure as well as according to specific features.

DIN rail conditioners are very popular in industrial applications since they provide a rugged mounting format for either a few or a large number of signal conditioners. Compatible with a broad range of device outputs such as thermocouples, RTDs, Heat Flux thermopile, load cells, and more for process monitoring and control. Layer N Modbus interface brings edge computing capabilities of Smart Interfaces into an existing Modbus network with RS Transmit data to a computer device or a smart gateway for cloud connectivity.

Backplane Mount Conditioners Certain signal conditioners can also be mounted on a common backplane. The backplane style provides the advantage of all output signals being accessible through a single common connnector. The backplane style signal conditioners are often used with data acquisition systems since a single cable can connect multiple conditioners to a data acquisiton device.

Digital Signal Conditioners Digital conditioners are one of the more recent developments in signal conditioners. The output of a digital signal conditioner is converted to a digital format such as RS , RS or even Ethernet.

Digital signals have several advantages over analog signals. They provide a high degree of immunity from electrical noise, they can also support extended transmission distances and are easily connected to a computer. With an ethernet output, the input signal can be read across an entire network or even across the internet if so configured.

From current, voltage, thermocouple, RTDs, and potentiometer to linear resistance signals, the device makes it easy to connect the most common sensors without requiring a separate signal conditioner for each. However, in the case of a universal signal conditioner, there is only one input and one output. A signal conditioner and isolator are often useful in applications where the signals from the source to the measuring device are required to be transmitted without a physical connection.

Isolators also prevent undesirable ground loop currents and protect the control system from transients and electrical noise produced due to unpredictable field conditions. A signal conditioner splitter accepts one input signal and splits the output into two identical signals through two separate channels. The ratio of signal strength to unwanted background interference is known as the signal-to-noise ratio. Amplification is the process of increasing this ratio by magnifying the voltage level of the input signal.

Converting a mV signal to a 0 V signal is an example of amplification. Attenuation, by contrast, is the process of decreasing the input amplitude, for example, to get it to fit within the optimal range of the device digitizer. Signal conditioning often requires the input signal to be filtered and isolated to remove unwanted background noise and remove voltage signals that are far beyond the range of the in-line digitizer. Filtering is commonly used to reject noise outside of a pre-defined frequency range.

Isolation is similar, but it is mainly used to protect the data acquisition or control system from voltage spikes that could damage the equipment. Excitation is required for many types of transducers. External power is required for the operation of an active sensor. For example, strain gages, accelerometers, thermistors, and RTDs require external voltage or current excitation.

Linearization is a form of signal interpretation that is used when sensor equipment produces signals that do not exhibit a linear relationship to the actual measurement. It is used to map the voltage of the input signal from the sensor against the corresponding value of the physical measurement.

This is a common signal conditioning process for industrial temperature measurements. A signal conditioner is a device that converts one type of electronic signal into a different kind of signal. Its primary use is to convert a signal that may be difficult to read by conventional instrumentation into a more easily read format.

In performing this conversion, several functions may take place. Understanding the signal conditioning needs for each measurement type is an essential aspect of achieving the best measurements. There are specific signal conditioning needs based on the sensors you require to perform an application. The most common temperature sensors used to measure temperature are Thermocouples, RTDs, and Thermistors. Protection of field signals in case of failure Signal conditioners protect the field circuits in the event of a short circuit.

Otherwise, the faulty circuit may shut down the entire supply chain and could cause damage to the wiring. Signal conditioners offer short circuit protection for each circuit of the field device.

If a single circuit fails, the other circuits are not affected. Protection against surges Signal conditioners protect personnel and equipment from dangerous voltages. In case of failure, high AC voltages or voltage pulses can enter the measuring circuit. Signal conditioners prevent the passage of high voltages into the control-side loop by galvanic isolation.

Personnel and equipment are protected from dangerous high voltages. Reliable signal doubling signal splitting Signal conditioners double input signals.

Potential equalization within a channel Signal conditioners adapt sources and sinks within a signal circuit. Quick Links. Go To.