Choosing between the Graphtec Midi Logger GL220 and the WitMotion WT901SDCL-BT50 really comes down to one question: are you logging wires or motion? These two data loggers answer that question in very different ways, and the right pick depends on the signals you need to capture.
Quick verdict
If your project involves electrical signals and process signals, the Graphtec Midi Logger GL220 is built for the job. If your project is about motion, the WitMotion WT901SDCL-BT50 covers that with wireless reading. Choose the logger that matches the signal you need.
Comparison at a glance
| Graphtec Midi Logger GL220 | WitMotion WT901SDCL-BT50 | |
|---|---|---|
| Price | $450.00 | $96.99 |
| Price position | ||
| Signal coverage | Voltage, current, power, pulse/event, count | Acceleration, gyro, angle, magnetometer |
| Channel / axis capacity | 10 channels | 9-axis motion, 200Hz |
| Connectivity | USB | Bluetooth 5.0, Type-C, SD card |
| Condition | Used | Open box |
Where each product wins
- Graphtec Midi Logger GL220 is the pick when you need to capture multiple signals at once. It handles the measurement types that many quality-control and research benches need, and it sends data straight to a computer.
- WitMotion WT901SDCL-BT50 is the pick when your data is motion. It combines wireless remote reading with onboard storage, so you can log without a wired setup and pull the data later.
Product notes
Graphtec Midi Logger GL220
The Graphtec Midi Logger GL220 earns its place with 10 channels and broad electrical-signal coverage: voltage, current, power, pulse/event, and count. For anyone managing several inputs in one session, that is a significant convenience. That makes it a solid one-box choice for bench testing, quality control, or research setups where multiple inputs need to be captured together. The USB connection keeps data transfer simple when the logger sits beside a computer. The main trade-off is the used condition, so the unit should be evaluated on how it fits your tolerance for pre-owned equipment. It also relies on a wired USB connection, which points it toward stationary work rather than remote logging.
WitMotion WT901SDCL-BT50
The WitMotion WT901SDCL-BT50 is a 9-axis motion logger with Bluetooth 5.0 remote reading and a built-in 16GB SD card. It records acceleration, gyroscope, angle, and magnetometer data, with XY angle specified at 0.05°, making it well suited to inclinometer and orientation tracking. The combination of Bluetooth and SD card storage means data collection doesn't have to happen next to a computer. The Type-C interface handles both data and charging, and the 50m Bluetooth range gives you room to capture from a distance when there are no walls in the way. The open-box condition is the limitation here, so it pays to check that the included components are present and intact. Battery life is about 10 hours, which is reasonable for a day of untethered logging.
Final choice by use case
Pick the Graphtec Midi Logger GL220 at $450.00 when you need a multi-channel recorder on a bench. Pick the WitMotion WT901SDCL-BT50 at $96.99 when you need motion logging. The price spread between the two is about $353, but the deciding factor should be the signal you are trying to capture: wires and process signals point to the GL220; motion and orientation point to the WT901SDCL-BT50. Base the choice on how and where you'll collect the data.
