Monitoring & metering
Figure 6. A signal chain of a detector system.
works as an electrometer amplifier, which benefits from not only the low input bias current, but also the low noise and offset. The ADA4530- 1 is also an operational amplifier with a 2 MHz gain bandwidth product, so the feedback resistor of gain can be very high as the signal bandwidth is normally less than several kHz. Cascaded ADA4522-2 devices with ultralow noise and drift amplifier as the second stage amplifier achieve sufficient gain for ADC input range. The ADA4522-2 offers zero drift op amps with low noise and power, ground sensing inputs, and rail-to-rail output, optimised for total accuracy over time, temperature, and voltage conditions.
Power Supply
The system power supply is derived from 24 VDC, and it is connected to step-down converters (buck) to provide the power supply for circuitry including amplifier, ADC, processor, and so forth. Both the LT8471 and the LTM4655 are dual outputs with positive and negative voltages. The LTM4655 with included controllers, power MOSFETs, inductors, and filters in the signal chain is designed to reduce design complexity while having a good EMI immunity.
CONCLUSION
Gas chromatography plays an important role in monitoring pollutants for the protection of our environment. It also has the potential and capability to be integrated into other techniques such as liquid chromatography in
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In general, gas chromatography is also convenient to be integrated into other techniques including liquid chromatography for the measurement of more substances. Therefore, it has become a widely used
August 2024 Instrumentation Monthly
order to measure and monitor more substances. To address the needs of today and those that may emerge tomorrow, ADI has a wide variety of low noise and high accuracy solutions to meet customer requirements and simplify system design.
Water Quality Monitoring Figure 7. A power supply chain for the system.
The surface water and groundwater are mainly contaminated by nitrobenzene compounds and heavy metal ions. Dissolved contamination will remain due to incomplete transformation during industrial production, and it poses a serious threat to public health. Gas chromatography can monitor contamination with high accuracy.
Soil Residual Pesticide Monitoring
In agricultural activities, the pesticides that farmers spray on their crops kill pests, but they can also damage people’s health. Gas chromatography can analyse the ingredients of pesticides accurately.
technique across most industries and testing facilities. Meanwhile, ADI can offer low noise and high accuracy signal chain solutions to reduce the complexity of system design and achieve excellent performance with high resolution, robustness, etc.
Analog Devices
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