Portable scope combines precision with long-term memory

Article By : Yokogawa

The DL350 adds high levels of precision, isolated inputs for measurements at high voltage levels and long-memory capabilities that allow recording for many hours or even days.

Yokogawa has launched the DL350 ScopeCorder, a portable measuring instrument for capturing, displaying, recording and analysing electrical and physical parameters in industry sectors including automotive, electronics, energy, transport and mechatronics.

Yokogawa’s DL350 combines features of a general-purpose oscilloscope and a high-performance data acquisition recorder. The company noted that unlike alternative portable measuring products, such as oscilloscopes and combined oscilloscope/multimeters, the DL350 adds high levels of precision and accuracy to field measurements, isolated inputs for measurements at high voltage levels and long-memory capabilities that allow recording for many hours or even days.

Another key feature of the DL350 ScopeCorder is its plug-in modularity, which allows it to be configured to suit a variety of user applications. The DL350 can carry out straightforward high-precision voltage measurements or handle a blend of signals coming from current probes, temperature sensors, strain gauges, accelerometers and serial buses without the need of extra boxes or cables, Yokogawa added.

The device's input capability is achieved by incorporating two slots that 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 1 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 100MS/s with 12bits and 1kV of isolation. There are 16 logic inputs always available, with even more available by swapping another 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. Users will benefit from the features and functions they know which are also present in the DL350 but in a 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 features, including comprehensive triggering and flexible memory use. Using the history memory enables up to 1,000 separate triggered acquisitions to be captured to the internal memory so that the causes and effects of abnormalities can be carefully analysed.

Up to 5Gpoints 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 100Mpoints per module of internal memory is available to capture fast transients. This 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, 100MS/s inputs, which can precisely measure and record transient waveforms (superimposed on inverter outputs, for example) and the edges of control signals that cannot be measured by traditional handheld recorders or oscilloscopes.

Its 8.4-inch resistive touchscreen can be used in environments with the highest levels of electrical noise, such as motors and inverters, to maintain precision whilst enabling the unit to be operated using gloved hands or a stylus. Even when the backlight is switched off and the touchscreen is inactive, the user still has access to the START/STOP, manual trigger and data saving keys. The device also has a built-in instruction manual.

Users have a choice of a simple level trigger or enhanced triggers for things such 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 40Hz to 1kHz waveforms).

The 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 but also provides the functionality of 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 analyse engine rotation and performance.

The power in single and 3-phase systems can be evaluated. In addition, for fundamental waveforms of 50Hz or 60Hz, up to 40 harmonic orders can be analysed. 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 that, when combined with either mains or 10–30V DC power, provides the DL350 with a reliable power supply for recording tests that are difficult or expensive to repeat.

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