Trade.Information

Product Name: Signal Conditioning

Product Description

National Instruments, the market leader in PC-based data acquisition, offers the most complete family of modular, plug-and-play data acquisition systems for virtually any sensor or signal type. NI data acquisition systems provide sensor- and signal-specific conditioning to improve your measurement accuracy by 10X.

National Instruments offers a wide variety of signal conditioning products that can improve your measurement system accuracy and performance by up to 10X. Conveniences such as USB connectivity and IEEE 1451.4 smart TEDS sensor support simplify configuration and reduce your time to first measurement. National Instruments signal conditioning products provide seven key technologies that simplify sensor connectivity, remove noise, ensure safety, and improve accuracy.

Key Technologies



Amplification
Amplifiers boost input signal level to better match the analog-to-digital converter (ADC) range, thus increasing the measurement resolution and sensitivity. In addition, using external signal conditioners located closer to the signal source, or transducer, improves the measurement signal-to-noise ratio by boosting the signal level before it is affected by environmental noise.



Attenuation
Attenuation, the opposite of amplification, is necessary when voltages to be digitized are beyond the digitizer input range. This form of signal conditioning decreases the input signal amplitude so that the conditioned signal is within ADC range. Attenuation is necessary for measuring high voltages.



Isolation
Isolated signal conditioning devices pass the signal from its source to the measurement device without a physical connection by using transformer, optical, or capacitive coupling techniques. In addition to breaking ground loops, isolation blocks high-voltage surges and rejects high common-mode voltage and thus protects both the operators and expensive measurement equipment.



Multiplexing
By multiplexing, a measurement system can sequentially route multiple signals into a single digitizer, thus providing a cost-effective way to greatly expand the system channel count. Multiplexing is necessary for any high-channel-count application.



Filtering
Filters reject unwanted noise within a certain frequency range. Nearly all data acquisition applications are subject to some level of 50 or 60 Hz noise picked up from power lines or machinery. Most signal conditioners include lowpass filters specifically designed to provide maximum rejection of 50 to 60 Hz noise.



Excitation
Excitation is required for some transducers. For example, strain gages, thermistors, and RTDs require external voltage or current excitation signals. RTD and thermistor measurements usually are made with a current source that converts the variation in resistance to a measurable voltage. Strain gages, which are very-low-resistance devices, typically are used in a Wheatstone bridge configuration with a voltage excitation source. 



Cold-Junction Compensation
Cold-junction compensation is a technology required for accurate thermocouple measurements. Any time a thermocouple is connected to a data acquisition system, you must know the temperature at the connection point (as this junction represents another "thermocouple" in the measurement path and typically injects an offset in your measurement) to calculate the true temperature your thermocouple is measuring.
What Is Signal Conditioning?

Signal conditioning turns your data acquisition device into a complete data acquisition system by helping you directly connect to a broad range of sensor and signal types, from thermocouples to high-voltage signals. Key signal conditioning technologies improve overall data acquisition system performance and accuracy by up to 10X

Company Details

In 1976, three talented entrepreneurs seeded the Measurement Revolution by launching a little-known startup named National Instruments. Throughout its history, NI has defined that revolution -- the dynamic development of computer-based and... more