VersaLog VL-RTD-1

  • 16-bit Analog-to-Digital Converter
  • 8-megabyte memory stores up to 4 million measurements
  • 1 On-Board Thermistor Channel
  • 4 RTD Input Channels
  • USB, Serial and Optional Ethernet Interface Capabilities
  • 10-year Battery Life
  • Alarm Output
  • SiteView software required (1 license per site) and sold separately


Additional Equipment Required


The VersaLog VL-RTD-1 RTD Temperature Data Logger

The VersaLog VL-RTD-1 RTD Data Logger is a 4-channel, battery-powered, standalone temperature data logger.  It records the ambient temperature with a built-in thermistor and has four external 2 or 3 wire RTD inputs plus alarm output capabilities. Data is stored in 8 MB of non-volatile flash memory for later retrieval.

The VL-RTD-1 is a high accuracy device, its 4 external RTD channels offer accuracy of +/-0.16°C @ 25°C. It accepts standard 2 or 3 wire PT-100 RTD probes that have a resistance value of 100 ohms at 25°C. It is powered by a 16-bit ADC and is well suited to science and laboratory applications where precise and accurate measurement is critical.

The VL-RTD-1 RTD data logger features an aluminum enclosure and provides excellent performance in the harshest industrial environments. It has both USB and serial interfaces and can connect to Ethernet networks using the optional DSS-2 device server.  The VL-RTD-1 is powered by an internal non-rechargeable lithium battery with up to 10-year life.

Memory Capacity

All VersaLog data loggers come with 8MB onboard flash memory. The following table shows the relationship between the number of enabled channels, sampling interval, and max time span of logging.

Sampling Interval Number of Channels Logging Capacity
1 min 1 7.96 years
1 min 2 3.98 years
1 min 8 362 days
10 sec 1 1.33 years
10 sec 2 242 days
10 sec 8 60 days
1 sec 1 48 days
1 sec 2 24 days
1 sec 8 6 days
100 milliseconds 1 116 hours
100 milliseconds 2 58 hours
100 milliseconds 8 14.4 hours


Connections Pluggable terminal block for four external channels, excitation controls, and alarm outputs
Channels On-board ambient thermistor temperature sensor (-40°C ~ 70°C). Four external RTD channels for 2 or 3 wire PT100, 100 ohm RTD’s, measurement range 20 ~ 400 ohms (-200°C ~ 850°C) Alpha .00385 & .00392 curves.
Resolution 0.0018%, 0.02°C
Accuracy Internal thermistor channel: +/- 0.2°C (0°C ~ 70°C) External RTD channels: +/- 0.015% FSR @ 25°C, +/-0.16°C @ 25°C
Channel Alarms Two editable alarm thresholds per channel
Alarm Outputs ALARM1 & A2/EXT terminal strips can be configured as alarm outputs
Alarm-On: MOSFET (N-Channel) switch on Alarm-Off: MOSFET (N-Channel) switch off
Max Power: 200mA @ 24VDC
Can report alarm status to host PC via USB, Modem or Ethernet Device Server with SiteView software[2]
Alarm-On Delay Programmable 0 – 10 minutes delay with 1-minute increments
Alarm Indicator On-board LED lights in red when in alarm condition
On-Board Memory
Capacity 8 megabytes (~4 million measurements)
Data Retention Over 20 years
Sampling & Logging
Sampling interval 20 milliseconds[1] to 12 hours user selectable
Logging Mode Stop recording or FIFO when memory is full
Logging Activation Programmable instant, start delay or field push-button activation
Interface USB (USB cable included), AUX (RJ11) for direct TTL level communications
Can be connected to Ethernet for remote access with DeviceServer Kit[2]
Baud Rate Auto-detect baud rate from 2400 to 115200 bps on both USB and AUX ports
Power Built-in 3.6V Lithium Battery
Life Cycle 10 years based on 1-minute sampling interval
SiteView Configuration, downloading, plotting, real-time view, custom calibration, and custom equations
Software Requirements Computer with 1.0 GHz or faster processor, 256 MB Memory or higher & 1.0 GB of available hard-drive space or higher
Windows XP with SP2 or later, Vista, Windows 7, 8, 10
At least one USB port or one COM port
LED Indicator Normal Sampling: green when sampling
Alarm: red when sampling
ow Battery: amber when sampling
Excitation Control A2/EXT terminal strip can be configured as excitation control output for powering connected devices
Warm-up delay Interval settings: 10 to 240 seconds with 10-second increments
Operating Environment -40 ~ +70°C (-40°F ~ 158°F), 0~95%RH non-condensing
Clock Accuracy +/- 1 minute per month
Approvals CE, FCC


Siteview Software

VersaLog SiteView Software

SiteView is a Windows-based application which works with the VersaLog Series data loggers for downloading, configuration, data analyzing and plotting. Its user-friendly graphic interface plus powerful functionalities fit both novice and advanced users.

The versatility of custom equations and custom-line equations handles complicated measurement requirements.

  • Supports USB, Serial port and Ethernet connections for easy local and remote access
  • Fast communication speed up to 115200 bps makes downloading fast
  • Real-time viewing and graphs replace obsolete paper chart recorders
  • Custom equation and custom-line equation solve scientific and laboratory algorithm difficulties
  • Zoom in/zoom out, annotation/label of graph functions provide a detailed view of data
  • Multiple file loading allows easy data comparison
  • Dynamic statistics provide detailed information on the current zoomed view