Manual
Table Of Contents
- Quick Start
- Overview
- Connecting the Logger to Your PC
- Setting Up the Logger To Record Data
- Custom Interval Setup
- Alarm Setup
- Using the Software to Check Logger Status
- Ending the Logging Session
- Powering Down the Logger
- Loading Logger Data
- Automatic Data Retrieval
- Working With the Data Graph
- Using the Zoom Feature
- Data Listing Window
- Data Summary and Statistics
- Using the Data Filter
- Hiding or Viewing Channels
- Exporting Logger Data
- Printing the Logger Data
- Calibrating the Logger
- Setting the Calibration Password
- Setting the Logger Real Time Clock
- Data Security
- Specifications
- MTL-30 Temperature Humidity Logger
- MTL-30 Logger Status LED
- Replacing the MTL-30 Battery
- MTL-30 Specifications
- MTL-20 Temperature Logger
- MTL-20 Logger Status LED
- Replacing the MTL-20 Battery
- MTL-20 Specifications
- GDL Temperature Humidity Logger with Display
- Turning the GDL On and Off
- GDL Sample Screen
- The GDL Summary Screen
- GDL Graph Screen
- GDL Buttons
- Replacing the GDL Battery
- GDL Specifications
- GDL-T Four Temperature Logger with Display
- Turning the GDL-T On and Off
- GDL-T Sample Screen
- GDL-T Difference Screen
- GDL-T Summary Screen
- GDL-T Graph Screen
- GDL-T Buttons
- Replacing the GDL-T Battery
- GDL-T Specifications
- MTL-LCD Loggers with Display
- MTL-LCD Display and Button
- Replacing the MTL-LCD Battery
- MTL-20-LCD Specifications
- MTL-30-LCD Specifications

DwyerLog User’s Guide Version 1.4x 31/33
• Display +: Use this button to increase the screen contrast when in Sample and Summary screens. When in
the Graph screen this button shifts the graph to the right. When in Graph Select screen, this button selects
the channels to graph.
• Display -: Use this button to decrease the screen contrast when in Sample and Summary screens. When in
the Graph screen this button shifts the graph to the left.
Replacing the GDL-T Battery
For instructions on how to replace the GDL-T battery, please see the section Replacing the GDL Battery.
GDL-T Specifications
Text Display
Displays real time temperature for all 4 channels. Displays temperature
difference between channels. Displays logging summary, sample rate, memory
used and memory left.
Graph Display
Shows measurement trends graphically. Graph can be scrolled through the entire
logged data. 2 Channels at a time can be graphed (user selectable).
Sample Storage
Capacity
21,760 points for 4 temperatures, 29,013 points for 3 temperatures, 43,520 points
for 2 temperatures, 87,040 points for single temperature.
Alarms
Visual over and under alarm indicator for all 4 channels.
Calibration
User single point offset calibration is available through software for all
temperature channels. Calibration is password protected.
Operating Temperature
15°F to 150°F (-10°C to 65°C)
Storage Temperature
-5°F to 160°F (-20°C to 70°C)
Time Accuracy
+/-100ppm @75°F
External Probe
Temperature Range
-40°F to 160°F (-40°C to 70°C)
Temperature Accuracy
+/-1°F (0.5°C)
Temperature Resolution
0.1°F or 0.1°C
Dimensions
4’’ x 3.05" x 1.5’’ (10.2cm x 7.7cm x 3.8cm)
Weight
7.0 oz (200g)
Power Source
Three AA batteries (Included)
Battery Life
1 year continuous use, 2 years average use. The logger automatically turns itself
Off after 1 hour, when not logging. Turn On by pressing any button.
MTL-LCD Loggers with Display
The MTL-LCD Temperature and Temperature/Humidity loggers are self-contained, precision instruments for
recording the temperature and relative humidity of the surrounding environment. The MTL-20-LCD records
temperature only and can store up to 43,344 temperature samples. The MTL-30-LCD records both temperature and
humidity and can store up to 43,344 temperature samples, or up to 21,672 of both temperature and relative humidity
samples. In addition to Temperature and Humidity, the DwyerLog software computes and displays the Dew Point
Temperature for the MTL-30-LCD.
MTL-20-LCD and MTL-30-LCD loggers have a digital display that shows the current temperature and humidity
(for MTL-30-LCD) reading, current recording state and the alarm condition.
The MTL-30-LCD logger temperature and relative humidity sensors are open to the air. It is therefore important to