DOP3000 series overview

Like all other ultrasonic Doppler velocimeters manufactured by Signal Processing SA, the DOP3000 series uses pulsed ultrasonic echo technique to measure velocity profiles. This series of instruments have been designed in order to fit user's request in terms of specifications and ease of use.

The DOP3000 series measures instantaneously velocity profiles, Doppler energy profiles, echo profiles, spectral density (FFT), histogram and many other data profiles. It computes and displays in real time these data profiles based on the analysis of a user’s specified number of gates placed along the ultrasonic beam.

All the ultrasonic parameters (PRF, TGC..) and the processing conditions (number of gates, starting depth) can be defined automatically or set by the user. The smart trigger capability of the instrument allows to synchronize the acquisition to any periodic or non periodic event. This high flexibility also applies to any of the 10 channels of the intergrated multiplexer of the DOP3010, and up to 32’000 profiles could be recorded in binary and/or ASCII format. If desired, the DOP3000 series can record simultaneously two types of data profiles, such as the velocity profiles and the Doppler energy profiles.

Operating in a Windows 98, XP or Vista environment, the velocimeter transfers all the acquired data through its build in USB interface to an external PC or laptop. It will be adapted to your applications with only few mouse clicks. The measured profiles can be recorded in binary or ASCII format within few milliseconds.

The key features of Signal Processing's DOP3000 series of velocimeter

	A USB instrument: Plug and play, small and lightweight device... Unlike the DOP2000, the DOP3000 series has no embedded computer. An external PC desktop or laptop controls the instrument through its built-in USB interface. This flexible solution allows to use the DOP3000 in all kinds of situations.
	An easy-to-use instrument: Operating parameters automatically computed... Based on very simple indications given by the user, such as the depth of measure along the ultrasonic beam and the maximum velocity to be measured, the brand new UDOP software delivered with the DOP3000 automatically computes most operating parameters (TGC, PRF, scale factors, number of emissions per profile). Tedious manual setting can therefore be avoided. Of course, advanced users can still fine-tune all these parameters or bypass this automatic mode. The DOP3000 also lets the user to set a quality factor of the measure, which defines an optimal trade-off between signal to noise ratio and sampling rate.
	The sensitivity The sensitivity is a very important parameter because it influences the range of possible application of the instrument. A high sensitive instrument allows measurements in liquids containing few particles and/or in liquids having high attenuation coefficient. The sensitivity is defined as the minimum instantaneous power of the Doppler echoes from which Doppler information can be extracted and is expressed in dBm (reference power 1mW on a 50 ohm impedance). Unfortunately, for most ultrasonic Doppler instruments find on the market, any numbers characterizing the sensitivity are not given. This makes the comparison difficult. Signal Processing has a put a lot of effort to offer very high sensitive instruments. This is why when many other instruments failed the DOP3000 series of ultrasonic velocimeter still deliver quality information.
	The resolution The definition of the thickness of the sampling volumes are not only defined by the ultrasonic burst length as it some times mentioned. This would be the case only if the electronic bandwidth of the instrument was infinite. This is never the case as all ultrasonic instruments owns filters to rejected unwanted noise level. The bandwidth reduction defines the minimum thickness of the sampling volume. In order to realize the best compromise between the noise level and the desired resolution, the DOP3000 series of velocimeter can modify both the burst length and the bandwidth of the receiver stage.
	More than one instrument The DOP3000 series of ultrasonic velocimeters do not only measure velocity profiles. They also can compute and display in real time other data profiles such as the echo, the Doppler energy and the power spectrum of a gate. They also offers the capability to measure the sound velocity in any liquid, or could be transformed in a complete acquisition system, capable of controlling up to 10 ultrasonic probes independently, each probes having its own set of parameters. The way we design our velocimeters offers to our customers a very versatile instrument that allows for instance to collect and record raw data they can send us via emails. This opens the possibility to evaluate any customer's processing methods and ideas, and therefore to advise them so that they can improve the way they use their DOP velocimeter.

The investigated liquid must contain particles. The size of the particles must be smaller than the wave length in order to avoid any diffraction of the ultrasonic beam. Hopefully this is often the case and most liquids contain enough very small gas bubbles, dust or impurities. And when it is not the case, we can provide seeding solutions.

The ultrasonic probe can be placed directly in contact with the liquid or coupled to the wall of the container by means of an ultrasonic gel. The coupling medium guarantees a path for the ultrasonic waves.

One of the most important parameter is the choice of the ultrasonic probe. This choice is generally based on:

All the ultrasonic parameters (ultrasonic frequency, pulse repetition frequency - PRF, time gain controlled amplification - TGC..) and the processing conditions (number of gates, filters...) can be either defined by the user, or automatically computed by DOP3000 software, UDOP, thanks to its new assisted mode. The optional smart trigger capability of the instrument, allows to synchronize the acquisition to any periodic or non periodic event. Profiles can be recorded in binary or ASCII format.

Operating in a Windows 98, XP, or Vista environment, the UDOP software that controls and communicates with the DOP3000 series of ultrasonic velocimeter through its USB port is easier than ever to use and to tune to fit your applications.

DOP3000	DOP3010