Mark Patrick, Mouser Electronics
One piece of advice often given in business is “If you measure it, it will improve.” As a result, many factories and other business premises have highly automated data acquisition (DAQ) systems to monitor and even control machines and processes. Any parameter that can be turned into an electrical signal via a sensor, including temperature, pressure, vibration, sound, voltage, current, acceleration, strain, light intensity, RPM and flow rate, can be measured and stored. Additional circuitry can take action based on preset thresholds, such as shutting a machine down, sending a message to a supervisor to inform them of a problem or even turning a fan on to cool a machine.
There are many different uses of DAQ, although the most important in a factory are to monitor and ensure quality of the product/process as well as monitoring the machinery itself and predicting the need for maintenance before a breakdown occurs. If the machine is allowed to break down, downtime is a likely result, which is often very expensive. Depending on the parameters associated with the application, the DAQ system will need to be configured with different numbers of channels and levels of resolution and accuracy.
Manufacturing and industry in general face a constant challenge to increase efficiency and control costs while delivering ever-higher product quality in highly competitive and crowded markets. This requires monitoring an increasing number of process parameters which, consequently, leads to the need to develop ever more sophisticated DAQ hardware and software.
Increased environmental awareness means that companies performing tasks that could impact the environment (for example, processing water or generating electricity) need to monitor and address any impact from their activities.
Because of the increase in use of DAQ systems there are multiple off-the-shelf systems available. These range from simple plug-and-play data loggers to sophisticated multi-channel, multi-function systems that can be configured to a specific application.
Small Solutions for Special Applications
Advantech’s USB-4700 series can accept DAQ modules without requiring the user to even open the chassis; they simply need to be plugged in to access stored data. These versatile devices are cost-effective enough to be used in the home while being tough enough to be used in industrial scenarios, and in all instances provide a simple means to add control and measurement to any USB-equipped computer. The versatile USB-4716 includes 16 single-ended (8 differential), 16-bit analog inputs that are each capable of 200ksamples/s throughput. Also included are 16 digital I/O lines, a user counter and a pair of 16-bit analog outputs. The unit is self-powered from the USB connections and does not require any external power supply.
Designed for mechanical applications such as the measurement of strain and structural loads, the DAQ instruments from MonoDAQ are capable of accepting inputs from any sensor. The simple yet powerful DEWESoft DAQ software runs on a PC that receives data via EtherCAT. The MonoDAQ-E-STG isolated strain gauge amplifier provides an interface to load cells and strain gauges using any bridge configuration, programmable excitation and extremely low noise. The wide input range covers 100mV to 50V, and currents up to 20mA are also catered for via an onboard shunt.
The MonoDAQ-E-gMeter provides a sensing and DAQ solution in a single package. The solution incorporates an extremely low-noise tri-axis MEMS accelerometer and is used in many infrastructure applications including buildings, bridges and antennas, and for measurement of seismic activity. The units are easily placed throughout measurement locations thanks to the ability to provide power and data connections via a single cable. Another product, the MonoDAQ-E-ACC acceleration sensor amplifier, measures vibration with high precision. Suited to use with integrated electronic piezoelectric (IEPE) sensors, the unit also provides all necessary signal conditioning. The system is particularly useful in prediction of early failure through the monitoring of machine vibrations, especially those related to faults in bearings.
Recording humidity, temperature and barometric pressure data with individual date and time stamps, Extech Instruments’ RHT35 USB data logger encompasses humidity, temperature and barometric pressure. It has the ability to transfer up to 48,000 data points to a PC as a PDF file or a processable spreadsheet. Other features include a total of six languages, eight-location logger bookmark, a configurable sampling interval, settable alarm and password protection for the login.
Extech also offers the VB300, which is a G-force DAQ that can log shock and vibration over three axes within a ±18g measurement range. The VB300 is suited to a wide range of applications including the measurement of shock and vibration levels and peaks during transportation of goods. Powered by a 3.6V lithium battery, the DAQ includes a USB interface for configuration and data transfer to a host PC for analysis by the included software. Mounting is facilitated by the magnetic mounting base included, which can also be bolted to surfaces.
Another series of devices for measuring tri-axis acceleration are the Slam Stick high-speed ultra-portable rechargeable data loggers from Midé that are also capable of measuring temperature and pressure. USB connectivity is used to charge the Slam Sticks as well as allow access for configuration and retrieving data. Users are able to set the delay prior to each measurement as well as define the measurement duration and set trigger levels as necessary. The lightweight devices require nothing more than double-sided adhesive tape for mounting, and are finding applications in equipment monitoring and characterization of vibration.
Sophisticated DAQ Systems
ADLINK’s USB DAQ modules are highly accurate devices that are also cost-effective and convenient. Included within the system are the USB-2405 dynamic signal acquisition (DSA) USB module, USB-2401 universal-input USB DAQ module, USB-1210 DAQ module 4-CH, USB-7230/7250 isolated USB I/O modules, and USB-1901/1902/1903 8/16-CH 16-bit 250kS/s multi-function USB DAQ modules.
Alongside these, ADLINK also supplies several industrial-specification computers and PXI platforms, all of which are aimed at vibration and audio applications. All of ADLINK’s DSA modules can be used to assess the condition of machines through the monitoring of audio, noise and vibration.
The DSAs offer IEPE signal conditioning and are capable of 24-bit resolution with a sampling rate of 432ksamples/s. They are simple to connect to sensors such as accelerometers and microphones and offer four analog input channels, each of which can sample at up to 128ksamples/s per channel. The devices benefit from high-precision 2mA excitation and are stable over temperature. Users can select AC or DC coupling via software.
Anti-aliasing filtering is achieved through the use of 24-bit sigma-delta ADCs. This also suppresses out-of-band signal and modulator noise, providing good signal bandwidth at the Nyquist rate. As a result, the modules are ideal for use with high dynamic range signals in vibration and acoustic use cases. The modules can be triggered by either a digital or analog signal and multiple trigger modes (post, delay, middle, gated and pre-triggering), which eliminates the need for post-processing.
Also from ADLINK is the USB-2401, a 24-bit universal-input DAQ module that offers simultaneous sampling across four channels. The device is compatible with a multitude of popular sensors including thermocouples, load cells, strain gauges, RTDs and more. Each channel can be configured to measure a specific type of signal.
For convenience, a stand that allows wall mounting or desktop use is included. Sensor connections are made via simple screw-down terminals. This general-purpose DAQ offers high levels of measurement accuracy and resolution and is ideal for materials testing or other laboratory use. Programming is not required, as the free software included (U-test) permits all key functions to be tested.
The DAQ970A from Keysight remains compatible with its 34970A and 34972A models, yet offers high levels of flexibility and performance. The DAQ is capable of monitoring and converting up to 12 inputs from a variety of sensor types including DC and AC voltages, two- and four-wire resistance, frequency and period, capacitance, strain thermocouples, RTDs and thermistors.
The chassis has three slots and includes signal conditioning and a 6.5 digit DMM, both of which reduce the time needed to configure testing scenarios. The internal DMM boasts an auto-calibration function. The overall scan rate has doubled in comparison to earlier similar DAQs. Accuracy has improved by 90%, especially for voltage, current and resistance. The unit is capable of measuring large resistances (<1,000Mand low currents (1 to 100μAAC).
Looking to the Future
As investment in infrastructure grows and industry becomes more automated through initiatives such as the IIoT and Industry 4.0, so the need for DAQ technology will continue to increase. Another driver is the need for reduced cycle times and greater quality, and combining all of these factors will lead to a DAQ market that is worth US$1.7 billion by 2022, according to Global Industry Analysts. Confirming the strong growth, Market Insights sees the market being worth US$3.61 billion by 2026, based on a CAGR of slightly more than 6%.
As a result of the need for more data, and different types of data, DAQ technology must continue to develop rapidly, which will no doubt lead to continued product releases for some time to come.
Mouser Electronics
Authorized Distributor
www.mouser.com
Download Techmezine Android app on google play store: Download Now
