• 7 inch TFT color LCD screen
  • Ability to access additional (GL100) sensors & adapters
  • 20 analog input channels, expandable to 200 channels
    • All channels isolated
  • AC, DC, & rechargeable battery pack power sources
  • WLAN capable using optional WLAN Unit B-568
    • For remote monitoring and data logging
  • Smartphone access via GL-Connect app
  • Max sampling interval up to 10ms
  • Extend memory capacity with SD cards
    • Purchased separately, compatible up to 32GB
  • Flexible input system for a wide array of applications

What's in the Box

  • AC power adapter
  • Quick reference guide
  • Internal 4GB flash memory
  • Software & manuals (CD)
  • Calibration cert
  • 3-year warranty


The Graphtec GL840 data logger is a standalone multichannel data logger with isolated universal input. In addition to accommodating numerous measurements, the GL840 includes many communications options and advanced functions making it an incredibly versatile data acquisition instrument for a wide array of applications.

The GL840 has 20 analog input channels, isolated so that wiring errors or overloaded channels do not affect neighboring channels. The system is easily expandable to up to 200 channels by adding the optional B-566 terminal base unit and input terminal units (B-564 or B-565). Input terminal blocks can be connected directly via daisy chain or by using cable. This allows the input terminals to be placed in separate =locations depending upon the requirements of the application.

The GL840 has two SD card slots which support up to 32GB of memory which can hold over a year's worth of data depending upon the sampling rate. A full color, 7-inch TFT display allows user to view data in waveform or digital form while also displaying parameter settings.

The Graphtec GL840 includes a number of communications features which allows integration with other devices and easy file sharing. A wireless LAN module (B-568) can be added to connect the GL840 with Graphtec GL100-WL modules. This expands the measurement variety of the GL840 by utilizing sensors available to the GL100-WL which will relay data directly to the GL840. The GL840 can also be connected to a LAN via a WLAN access point. Measured data can then be monitored via a PC or smart device using the application software. Configuration can also be set via the network.


Here's how some of our customers use this product...

Creating Temperautre Maps

The Background: A consumer electronics company is creating a temperature map as part the development of a new product.

The Problem: Temperatures are taken at 27 points on the test surface. To identify emerging trends, the customer wants to log all the measurements.

The Solution: The Graphtec GL840 was paired with 27 Watlow thermocouples to create the matrix used for temperature measurement. The GL840 has 20 input channels and can be expanded to up to 200 channels. Multiple communications options make it easy to transfer data for analysis.