Data acquisition card

Finally, the recording of many signals from the output of the analytic and electrochemical instrumentation requires a reliable multi-pen recorder or an equivalent recording system based on a data acquisition card and appropriate software. The recorded signals are normally in the range of a few mV to 10V. The use of reliable temperature controllers and thermocouples is also crucial for the success of the experiments. A lot of suppliers of such equipment can be easily found and will not be reported here. 

Figure 16.4 Electrochemical screening instrumentation, consisting of a wave generator, a potentiostat, a current follower, and a PC with a data acquisition card [Guerin et al., 2004].

The intensities of the sample and reference beams are measured with photodiodes by an analog data acquisition card and/or digital oscilloscopes to calculate the absorbance of the sample. The time resolution of the photodiodes is not important for this application but it is essential that their photoresponse is strictly linear to the light pulse intensity. Each absorbance measurement can be corrected for the absorbed radiolytic dose by measuring the charge in the electron bunch using a Faraday cup or some other detector. At each pulse-probe delay, it is necessary to measure the sample absorbance in the presence and absence of the electron beam, the latter measurement serving as the baseline. In practice, since the probe beam transport distances in these facilities may be several meters or more, optical transport fluctuations due to vibration and air turbulence in the 40-100 ms interval between the sample and baseline measurements... 

J.S. Eid, J.D. Muller, E. Gratton, Data acquisition card for fluctuation correlation spectroscopy allowing full access to the detected photon sequence. Rev. Sci. Instrum. 71, 361-368 (2000)... 

Data of the relative electrical resistance changes from the 18 sensors can combine with every sample to form a matrix (see Fig. 2 The library data base) and the data is without preprocessing prior to chemometrics analysis. The sensor response is stored in the computer through data acquisition card and these data sets are analyzed to extract information. 

To facilitate data recording and storage, oscilloscopes with storage capabilities have been replaced by personal computers with A/D conversion-based data acquisition cards to record all transient measurement signals. 

Stress measurement 20 channels, multi-channel data acquisition card of high speed, piezoresistive and piezoelectric sensors. 

The outputs of the sensors are acquired in the PC through PCI data acquisition cards. The MOS sensors are conductometric in nature, and their resistance decreases when subjected to the odour vapor molecules. The change in resistance with respect... 

Measurement of the ECG is performed using a differential amplifier. Two limb electrodes at a time are selected for the input to the differential amplifier stage. ECG amplifiers typically have gains of about 1000 and so increase the nominally 1-mV biopotential to about 1 V for driving a strip-chart recorder, cathode-ray-tube display, or computer data-acquisition card. Chart speeds in ECG recording have been standardized at 25 and 50 mm/s. 

The data acquisition system included amplifiers, a data connection board (NI SCB-68, Austin, TX), a data acquisition card (NI USB-6251, Austin, TX), and a... 

The earthquake engineering experimental facility at Northeastern University provides large-scale dynamic testing of soil samples under uniform cyclic or earthquake motions. It includes a shaking table (Fig. 21.2), a data acquisition card (NI-DAQ) and software (LabVIEW), a set of instmments including accelerometers (Crossbow, Ig, 2g, 5g, Fig. 21.3a), linear variable displacement transducers (LVDT, RDP DCTH400AG, Fig. 21.3b), miniature pore pressure transducers (GE Druck PDCR 81, Fig. 21.3c), and multiple bender element and bending disk measurement equipment for S and P wave measurements (Fig. 21.3c-e). 

Utilizing a data acquisition card (NI-DAQ) and data processing software Lab VIEW. The shaking table has a load capacity of 25 kN and can effectively perform at a frequency range of 0-50 Hz. It incorporates MTS Model 244.21 actuator with a 254 mm stroke capability ( 127 mm lateral displacement) (Kadakal and Whelpley 1997). 

A prototype device of the conductivity and velocity (C-V) technique has been developed. The device mainly consists of three units, including a sample cell, a measurement unit, and a personal computer. The sample cell is made of stainless steel for aqueous samples under examination. The measurement unit is equipped with a conductivity meter with a 4-pole conductivity probe, an ultrasonic pulser/receiver with two ultrasonic transducers that are mounted on the two opposite sides of the sample cell. The measured electrical conductivity and temperature (by the conductivity meter) and the acoustic velocity (by the pulser/receiver) are acquired and sent to the computer by a high-speed data acquisition card. Specific software is developed and installed in the computer. The software is capable of determining salt and inhibitor concentrations using the measured conductivity, velocity, and temperature. By integration with a thermodynamic model HWHYD, the software can also determine the hydrate phase boundary, hence the hydrate safety margin given the hydrocarbon composition and the pipeline conditions. 

Early FTIR instruments required specialist computing resources, which partly explains their high cost. Today, the electronics which required a console the size of a small room to house them, can be contained within a PC of moderate performance and low cost, bolstered by fast data-acquisition cards, transputers or coprocessors. 

Digital input/output terminals are the basis for cooperation of sensor and data acquisition cards. A typical process of cooperation is to start the measurement of an external instrument by a digital trigger puke from... 

The injection of the tracer gas to the reactor was made by an automatic injection system, specially designed and controlled precisely by a personal computer. The readings from the anemometer were digitized and interfaced to the computer by a 12-bit data acquisition card. The PCLMP16 model card was purchased from The National Instruments Corporation. 

To cany out dual dynamic voltammetry experiments a computer-controlled multichannel electrochemical measming system is necessary. In the experimental setup described in [7,14-16] the basis of the system is formed by National Instruments data acquisition cards, combined with commercially available potentiostats and other laboratory devices, such as electrode rotating imits, quartz crystal microbalances, etc. Figure 2 shows the scheme of a typical experimental setup. 

The measuring equipment consisted of a PC running Labview software, with a data acquisition card (GPIB), a LeCroy Waverunner Oscilloscope, and a Ultrasonic Pulser/Receiver (see figure 7). 

---