Graphtec GL840-M 20-Channel Multi-Function Logger

£2058.00 (£2,469.60 inc VAT)

Available on back-order

SKU: GR-GL840-M Categories: ,


Graphtec GL840-M Multi-Function Logger

The GL840 is a compact, lightweight, multi-channel, and multi-purpose data logger with a 7-inch colour display. 20-channel measurements are available with the standard terminal (‘-M’ model) or high-voltage high-precision terminal (‘-WV’ model). 200-channel measurements are available with the extension terminal base. Furthermore, various optional modules are available for voltage, temperature and humidity, acceleration, AC current, CO2, and illuminance / ultraviolet measurements. The GL840 can save the high-capacity measurement data directly to the internal memory or to an SD memory card. USB and Ethernet is included as standard for connecting to a PC. The Ethernet function is equipped with both WEB server and FTP server functions, so that remote supervision and data transfer are also possible. Multipurpose remote measurement is also possible using the GL wireless unit (B-568) and Graphtec wireless Petit loggers (GL100-WL).

Standard accessories… Quick start guide, CD-ROM (user manual & application accessories), AC adapter & cable, ferrite core.


  • Flexible input system for wide array of applications
  • Wireless LAN capability for remote monitoring and remote datalogging system
  • Extended memory capacity using SD memory card
  • Maximum sampling interval of up to 10ms


Main Unit Specifications
Number of analogue input channels 20 channels in standard configuration, Expandable up to 200 channels
Number of analogue input terminals Up to 10 terminals (20 channels / terminal), standard config: 1
Type of analogue input terminal Multi-input type, Withstand-voltage type
Port for digital sensor 1 port for the sensor/input terminal/adapter of the GL100
External input/
output *1
Input *2 Trigger or Sampling (1 channel), Logic/Pulse (4 channels)
Output *3 Alarm (4 channels)
Sampling interval 10 ms to 1 hour (10ms to 50ms: voltage only) *4, External signal
Time scale of waveform display 1 sec. to 24 hour /division
Trigger, Alarm function
Trigger action Start or stop capturing data by the trigger
Repeat action Off, On (auto rearmed)
Trigger source Start: Off, Measured signal, Alarm, External, Clock, Week or Time
Stop: Off, Measured signal, Alarm, External, Clock, Week or Time
Condition Setting Combination: OR or AND
Analog signal: Rising (High), Falling (Low), Window-in, Window-out
Logic signal: Pattern (combination of each input signal in high or low)
Pulse (number of count): Rising (High), Falling (Low), Window-in, Window-out
Alarm output Outputs a signal when alarm condition occurs in the input signal
Pulse input function
Rotation count
(RPM) mode
Counts the number of pulses per sampling interval and converts to rpm
(rotations per minute), Number of pulses for one rotation can be set to
50, 500, 5000, 50k, 500k, 5M, 50M, 500M rpm/F.S. (rpm./Full Scale)
count mode
Accumulates the number of pulses from the start of measurement
50, 500, 5000, 50k, 500k, 5M, 50M, 500M C/F.S. (Counts/Full Scale)
Instant count
Counts the number of pulses per sampling interval
50, 500, 5000, 50k, 500k, 5M, 50M, 500M C/F.S. (Counts/Full Scale)
Maximum number of pulse inputs Maximum input frequency : 50kHz
Maximum number of count : 50kC/sampling (16-bit counter)
Calculation function
Between channels Addition, Subtraction, Multiplication, and Division for analog input
Statistical Select two calculations from Average, Peak, Maximum, Minimum, RMS
Search function
Search for analogue signal levels, values of logic or pulse or alarm point
in captured data
Interface to PC Ethernet (10 BASE-T/100 BASE-TX), USB (Hi-speed), WLAN (using B-568 option)
Storage device
Internal Built-in 4GB Flash Memory *6
External One SD card slot (Support SDHC memory card, up to 32GB) *7
Saved contents Captured data, Setting conditions, Screen copy
Back up recording data function
Backup interval *8 Off, 1, 2, 6, 12, 24 hour(s)
Backup file destination *8 SD memory card or FTP server
Data format *8 GBD (binary) or CSV (test)
Check-sum function (Verifies data file) OFF: Not adding check-sum code to data file.
ON: Adding check-sum code to data file. Check-sum code is verified when replaying data on the GL unit or GL-Connection software.
Capturing mode Mode: Normal, Ring, Relay
Ring: Saves most recent data (Number of capturing data: 1000 to 2000000 points) *9
Relay: Saves data to multiple files without losing data until dada capturing is stopped
Replay data Replays captured data that was saved in the GL840 (in GBD or CSV format)
Scaling (Engineering unit) function Measured value can be converted to specified engineering unit
• Analog voltage: Converts using four reference points (gain, offset)
• Temperature: Converts using two reference points (offset)
• Pulse count: Converts using two reference points (gain)
Action during data capture • Displaying past data (using dual display mode (Current + Past data))
• Hot-swapping the SD memory card
• Saving data in between cursors
Size 7-inch TFT color LCD (WVGA: 800 x 480 dots)
Language English, French, German, Chinese, Korean, Russian, Spanish, Japanese
Information *10 Waveform in Y-T with digital values, Waveform only, Digital value, Digital values
and statistics values
Operating environment 0 to 45 ºC, 5 to 85 % RH (non condensed)
(When operating with battery pack 0 to 40 ºC, charging battery 15 to 35 ºC)
Power source
AC adapter 100 to 240 V AC, 50/60 Hz (1 pc of adapter is attached as standard accessory)
DC power 8.5 to 24 V DC (DC drive cable (option B-514) is required)
Battery pack Mountable two battery packs (battery pack (option B-569): 7.2V DC, 2900mAh)
Power consumption Max. 38 VA
External dimensions (W x D x H
in mm, Excluding projections)
GL840-M: Approx. 246 x 161 x 58.2 (with the cover)
GL840-WV: Approx. 246 x 170.4 x 58.2 (with the cover)
Weight GL840-M: Approx. 1218 g (the cover is attached)
GL840-WV: Approx. 1244 g (the cover is attached)


Specifications are liable to change. For the full list of Specifications, please see the products datasheet located under the ‘Documentation’ tab.


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Optional Accessories …

  • Graphtec AF1450 Storage Case

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  • Graphtec GS-TH Temperature & Humidity Sensor

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  • Graphtec GS-3AT 3-Axis Acceleration & Temperature Sensor

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  • Graphtec B-566 Base Unit for Input Terminal

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  • Graphtec GS-103JT-4P Thermistor Sensor (-40°C to 120°C)

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  • Graphtec B-513 Input / Output Cable

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  • Graphtec B-570 DIN Rail Bracket

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  • Graphtec GS-103AT-4P Thermistor Sensor (-40°C to 105°C)

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  • Graphtec GS-DPA-AC AC Current Sensor Adapter

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  • Graphtec GS-EXC 1.5m Extension Cable

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  • Graphtec GS-DPA Branch Adapter

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  • Graphtec B-564 input Terminal for GL840-M

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