Complete measurements, complete portability

Like other models in Yokogawa's ScopeCorder family, the DL350 combines features of a general-purpose oscilloscope and those of a high-performance data acquisition recorder in a single, portable instrument. Unlike alternative portable measuring solutions such as oscilloscopes and combined oscilloscope/multimeters, it adds exceptionally high levels of precision and accuracy to field measurements, isolated inputs for measurements at high voltage levels, and long-memory capabilities that allow long-term recording for many hours or even days.

Another key feature of the DL350 ScopeCorder, which is not offered by other portable instruments, is its plug-in modularity, which allows it to be configured to suit a variety of user applications. Whether carrying out straightforward high-precision voltage measurements or handling a blend of signals coming from such things as current probes, temperature sensors, strain gauges, accelerometers and serial buses, the DL350 can deliver, without extra boxes or cables.

This flexible input capability is achieved by incorporating two slots which are populated with any of 18 different types of user-swappable input modules. This means, for example, that four isolated 16-bit voltage inputs can be measured at speeds of one megasample per second (MS/s) alongside 16 temperatures or two separate CAN or LIN buses each containing 60 signals. Changing a single module enables measurement at 100 MS/s with 12 bits and 1 kV of isolation. Meanwhile there are 16 logic inputs always available, with even more available by swapping a further module.

Among other modules are AC measurements using an RMS module in real time and a mathematics channel for signal processing and analysis after the recording is finished.

The DL350 offers compatibility with many existing ScopeCorder input modules and thereby provides a potential cost saving to existing users. They will also benefit from the features and functions they have come to value which are represented in the DL350 in a more portable package.

For users who are more familiar with chart recorders than with long-memory oscilloscopes, the DL350 offers a choice of operating modes. Recorder mode is suitable for long-term, continuous recording for a specific duration and where the sampling interval is specified. A set-up wizard can be used in this mode to guide the operator quickly through the entire set-up process.

Scope mode allows the DL350 to be used just like an oscilloscope with all the associated benefits, including comprehensive triggering and flexible memory use. Using the history memory enables up to 1000 separate triggered acquisitions to be captured to the internal memory so that the causes and effects of abnormalities can be carefully analysed.

Up to 5 Gpoints of data per module can be recorded directly to an SD card. This means that the DL350 can be used for continuous recording up to 50 days. For high-speed signals, up to 100 Mpoints per moduleof internal memory is available to capture fast transients. This is up to 10,000 times more than other portable oscilloscopes or oscilloscope/multimeters and allows signals to be captured with higher sample rates or over longer periods.

A high-resolution, high-speed sampling module, unique amongst portable measuring instruments, provides individually isolated 12-bit, 100 MS/s inputs, which can precisely measure and record transient waveforms (superimposed on inverter outputs, for example) and the edges of control signals which cannot be measured by traditional handheld recorders or oscilloscopes.

An 8.4-inch resistive touch screen has been adopted to deliver superior noise-free performance. In environments with the highest levels of electrical noise such as motors and inverters, measurement precision is maintained whilst enabling the unit to be operated using gloved hands or a stylus. Even when the backlight is switched off, and the touch screen is inactive, the user still has access to the START/STOP, manual trigger and data saving keys. For users unfamiliar with state-of-the-art measuring instruments, there is also help at hand via the built-in instruction manual.

The user has a choice of a simple level trigger or enhanced triggers on such things as pulse width, waveform period and across multiple channels. For example, the wave window trigger is ideal for AC power-line monitoring, and enables voltage sags, surges, spikes, phase shifts or drop-outs to be easily captured (available for 40 to 1000 Hz waveforms).

A DL350 can be left unattended with the captured waveform automatically saved to a file, or a notification email sent if and when it triggers.

The DL350 is first and foremost a field tool. However, it still provides the functionality users expect in a bench instrument. The sampling clock, trigger and start/stop controls are all available as external signals, so that a rotary angle encoder or degree wheel, for example, can be used as the sample clock to analyze engine rotation and performance.

The power in single and 3-phase systems can be evaluated. In addition, for fundamental waveforms of 50 or 60 Hz, up to 40 harmonic orders can be analyzed. Alternatively, it is possible to use the suite of FFT functions to perform full frequency analysis.

The DL350 is based on an A4-sized compact chassis and weighs less than 2.6Kg excluding battery and under 4Kg when populated with a battery and 2 x 4 channel modules. The built-in rechargeable battery provides three hours of continuous operation which, when combined with either mains or 10-30 V DC power, provides the DL350 with a highly reliable power supply and worry-free recording for tests that are difficult or expensive to repeat.