Choosing between two used data acquisition recorders usually comes down to cost versus capability. One option is a sub-$400 used system that includes signal conditioning hardware. The other is a used instrument priced in the four figures. Both are sold in used condition, so the decision rests on how much integration you need and how much you want to spend.
Quick Verdict
If your main concern is keeping the upfront cost down and you have time to inspect a used instrument, the DATAQ DI-720-USB is the lower-priced choice. If you want one unit that combines logging and meter-style measurement, the Keithley DAQ6510 is the more complete system. There is no wrong answer; the right one depends on your bench and budget.
Comparison
| Feature | DATAQ DI-720-USB | Keithley DAQ6510 |
|---|---|---|
| Price | USD 349.99 | USD 1,600.00 |
| Brand | DATAQ Instruments | Keithley |
| Condition | Used | Used |
| Country of Origin | United States | China |
| System descriptor | DI-5B amplifiers & MESA interface | DMM6500 Multimeter System |
| Model | DI-720-USB | DAQ6510 |
Where the DATAQ DI-720-USB wins
- The price gap is substantial, coming in more than $1,250 lower.
- It is a United States-origin unit.
Where the Keithley DAQ6510 wins
- It combines data acquisition and multimeter functionality into one unit.
- The two-slot design is a clearly listed attribute.
Product Notes
DATAQ DI-720-USB Data Acquisition System w/ DI-5B Amplifiers & MESA Interface
For a budget-minded shopper, this is an easy entry into data acquisition recorders. The main draw is the included DI-5B amplifiers and a MESA interface, which appear in the product title and save you from sourcing those components separately. The used condition, though, means you cannot assume it is ready to run. The seller notes it came from a university surplus, was very dusty, and is sold as-is without testing. Plan to clean it, inspect the connectors, and do your own verification before relying on it for measurements. If you are comfortable with a project-grade used instrument, the low price makes this an appealing foundation.
Keithley DAQ6510
The Keithley DAQ6510 is the more substantial commitment at a much higher price. What you get in exchange is a product title that pairs data acquisition with a DMM6500 multimeter system and a two-slot design, making it a more integrated bench tool. The model number is explicitly listed as DAQ6510, which gives you a concrete identifier. The trade-off is the premium price for a used unit; you are paying far more than the DATAQ system, so the condition and functionality deserve extra scrutiny. For a lab that wants one instrument to handle both logging and meter-style measurements, the DAQ6510 is the stronger fit despite the larger outlay.
Final choice by use case
If your goal is a low-cost entry with signal conditioning included, the DATAQ DI-720-USB fits. If you need a single data acquisition recorder that also works as a multimeter and has a two-slot layout, the Keithley DAQ6510 is worth the higher investment.
