When you need to capture multiple analog signals and keep a record of what happened, the buying decision usually comes down to two design styles: a modular acquisition front end with signal conditioning, or a single industrial unit that records and manages the process. Both options below are used units in the data acquisition recorders category, but they take very different approaches to the job.
Quick verdict
If your priority is a flexible analog input chain, the DATAQ DI-720-USB is the one to lean toward. If you would rather have one device that does the whole job, the Eurotherm Nanodac is the more complete package.
Price and package comparison
| Product | Listed price | Price bar | Condition | Origin | Key angle |
|---|---|---|---|---|---|
| DATAQ DI-720-USB Data Acquisition System w/ DI-5B Amplifiers and MESA Interface | $349.99 | Used | United States | Modular analog front end | |
| Eurotherm Nanodac Invensys Recorder Process Controller Data Logger Ethernet USB | $416.04 | Used | United Kingdom | All-in-one paperless recorder |
Where each product wins
Choose the DATAQ DI-720-USB when you already work with modular signal conditioning and want a dedicated acquisition front end. The DI-5B amplifier path and MESA interface are the practical reasons to build around it.
Choose the Eurotherm Nanodac when you need a single unit that records, displays, and responds to a process. The Ethernet, USB host, analog inputs, relay outputs, and data logging make it the stronger fit for a connected installation.
DATAQ DI-720-USB Data Acquisition System w/ DI-5B Amplifiers & MESA Interface
This is the right starting point for someone who wants a dedicated data acquisition setup centered on amplifier modules. The DI-720-USB unit is sold as a used surplus item, and the seller is upfront that it was very dusty when found and may need further cleaning. If you are comfortable with an as-is piece of gear and have time to clean it up, the DI-5B amplifier stage can be a practical way to condition multiple analog signals before they reach the acquisition system. The MESA interface adds another layer of flexibility. The condition risk is real, but the analog front-end focus is the reason to choose it.
Eurotherm Nanodac Invensys Recorder Process Controller Data Logger Ethernet USB
This is the more feature-dense choice of the two. The Eurotherm Nanodac is a genuine paperless recorder and process controller that was removed from a working system, so it shows normal cosmetic wear such as light scratches and minor marks on the bezel. In exchange for that used look, you get a color display, a USB host port, Ethernet communication, multiple universal analog inputs, relay outputs, and data logging in one enclosure. If your workflow relies on the recorder not just storing data but also responding to it, the built-in control capability is the standout reason to pick it. The trade-off is a used industrial unit that will not look pristine. The Nanodac is the right pick when you want a single, connected process instrument.
Final choice by use case
Choose the DATAQ DI-720-USB when you are building a modular analog acquisition setup and can accept an as-is unit. Choose the Eurotherm Nanodac when you need an all-in-one recorder/logger for a connected process setup.
