Site Search:

Model GL820 (Obsolete replaced by the GL840-M)

Handheld, 20- to 200-channel Data Logger

Out of


  • Includes a GL820 data logger, an AC adapter, an NIST-traceable calibration certificate, and software on CD
  • Built-in 5.7" TFT LCD Color Display
  • Stand-alone or PC-connected operation
  • 20 Analog Channels Standard, Expandable to 200
  • Input-to-output and channel-to-channel Isolation
  • USB and Ethernet PC Interfaces
  • Programmable measurements per analog channel:
    • 12 voltage ranges over ±20 mV to ±50 V full scale
    • Type J,K,T,R,S,B,E,N,W thermocouples
    • PT100, PT1000 3-wire RTD
  • Four discrete/counter/frequency input channels
  • Four alarm outputs
Tweet this page Like this product on Facebook Share this page on LinkedIn Email this page
GL820 Data Logger


With its color monitor and internal memory the GL820 is a compact, lightweight, multi-channel data logger that provides 20 standard analog measurement channels, expandable to 200. The GL820 is equipped with a large internal flash memory to allow the direct capture of acquired data, and its built-in USB port may be used to connect any standard USB flash drive for incremental capacity. Alternatively, the USB or the integral Ethernet port may be connected to a PC to allow data upload in real time or from memory, as well as local or remote configuration and real time data acquisition. The Ethernet feature includes WEB and FTP server functions, which allows monitoring from a remote location as well as data transfer.



4-20mA Current Loop Shunt Resistor

$ 2.99
R250 Shunt Resistor


250 Ω ±0.1% Precision, Metal Film, 1/2W, Axial Resistor
Exceptionally low noise; typically 0.10 μV/V
Low voltage coefficient to ±5 ppm/V
Flame retardant coating. RoHS compliant. Learn More


Logic/Alarm Cable

B-513 Graphtec Logic Alarm Cable


2-meter logic/alarm cable with bare tips.


DC Power Cable

B-514 Graphtec DC Power Cable


2-meter DC power cable with bare tips.


Battery Pack

B-569 Graphtec Battery Pack


One (1) 7.2V/2900mAh lithium battery pack. Please Note: Continental U.S. shipping ONLY.


Humidity Sensor

B-530 Graphtec Humidity Sensor


3-meter humidity sensor with dedicated power connector. Learn More.



B-536 Graphtec Carrying Case


Carrying Case. Interior padding and rugged exterior for safe transportation of your GL220 data logger. 4-6 WEEK LEAD TIME.



File Conversion

FREE Graphtec to WinDaq High Resolution (GBD - to - WDH) File Conversion Utility (beta version) converts files recorded with a Graphtec device to WinDaq Playback for analysis.

Graphtec to WinDaq file converter

Graphtec Downloads

Data Logger Software

Visit the Support Download page at Graphtec for software (both links below take you to another site).

Graphtec Downloads


Graphtec GL820 Playlist
GL820 Setup

View the GL820 Data Logger setup tutorial playlist on YouTube.
Graphtec APS Software Overview
Graphtec APS Software

APS PC-based software provides access to all the features on the front panel, and more.