LRTD SITE-LOG Resistance Temperature Detector Data Logger

The LRTD SITE-LOG is a rugged 4-channel RTD temperature data logger designed for multi-point temperature monitoring in industrial, laboratory, research, testing, and environmental applications.

It provides four external RTD input channels plus one built-in temperature channel for ambient temperature monitoring. Three models are available for PT100, PT500, and PT1000 RTD sensors:

• LRTD-1 – PT100
• LRTD-2 – PT500
• LRTD-3 – PT1000

The LRTD is a battery-powered, standalone logger with 8 MB of non-volatile flash memory, allowing temperature data to be recorded in the field and downloaded later through USB. Its rugged aluminum enclosure and conformal-coated PCB provide additional protection for long-term use in demanding environments. 

Multi-Channel RTD Temperature Measurement

The LRTD provides four external channels for resistance temperature detector measurements.

The supported resistance and temperature ranges are:

• PT100: 20 to 400 Ω, corresponding to approximately −200°C to +850°C
• PT500: 90 to 1600 Ω, corresponding to approximately −200°C to +630°C
• PT1000: 185 to 3200 Ω, corresponding to approximately −200°C to +630°C

Built-in equations support RTD sensors with temperature coefficients of resistance (TCR) of:

• 0.00385 Ω/Ω/°C
• 0.00392 Ω/Ω/°C

Custom equations can also be used for other compatible RTD sensors.

High-Resolution Data Logging

The LRTD uses a 16-bit analog-to-digital converter for high-resolution RTD measurements.

Typical temperature resolution is:

• PT100: 0.02°C
• PT500: 0.015°C
• PT1000: 0.015°C

Sampling intervals are programmable from:

20 milliseconds to 12 hours

This allows the same logger to be used for both fast testing and long-term temperature monitoring.

External power is required when the sampling interval is less than 1 second. 

Standalone Operation and Long-Term Recording

Recorded data is stored in 8 MB of onboard non-volatile flash memory and retained even when external power is removed.

Depending on the sampling interval and number of enabled channels, the logger can record from hours to years of temperature data.

The logger supports:

• Stop logging when memory is full
• FIFO logging mode
• Immediate logging
• Delayed start
• Field push-button activation

With a 1-minute sampling interval, the internal battery can provide up to 10 years of operation, depending on usage and operating conditions.

USB Communication and SiteView Software

The LRTD connects directly to a computer through USB.

SiteView software provides the tools required to:

• Configure logging sessions
• Select RTD equations
• Download recorded data
• View real-time readings
• Display data in graph and table formats
• Configure alarms
• Apply custom calibration and custom equations
• Export and analyze recorded data

SiteView is sold separately. 

Alarm and Excitation Control

The LRTD provides configurable alarm and control functions for applications requiring more than basic data recording.

Each channel supports two programmable alarm thresholds.

The available output terminals can be configured for:

• Alarm output
• Excitation control

The onboard status LED provides visual indication of normal sampling, alarm conditions, and low battery status. 

Remote Access and Network Integration

Although the LRTD is a USB-based data logger, it can also be accessed remotely over an Ethernet network by connecting it to a Microedge Smart-Hub.

Smart-Hub allows the LRTD to be accessed through:

• SiteView
• SiteView-Web
• SiteView SDK
• Pluto

Smart-Hub also provides:

• RESTful Web API
• Modbus TCP Gateway

This allows LRTD temperature data to be integrated with third-party software, PLCs, HMIs, SCADA systems, and other industrial monitoring platforms.

Smart-Hub Specifications Page

Rugged Industrial Design

The LRTD is housed in a durable aluminum enclosure.

Its circuit board is protected with conformal coating to help resist:

• Moisture
• Corrosion
• Mildew

The logger is designed for operation from:

−40°C to +70°C (−40°F to +158°F)

with up to:

95% RH, non-condensing. 

Key Features

• 4 external RTD input channels
• 1 built-in temperature channel
• Available for PT100, PT500, and PT1000 sensors
• Built-in equations for TCR 0.00385 and 0.00392
• Custom equation support for other compatible RTD sensors
• 16-bit analog-to-digital converter
• 8 MB non-volatile flash memory
• 20 ms to 12 hr programmable sampling interval
• USB communication
• AUX TTL-level serial communication
• Programmable alarm thresholds
• Alarm output and excitation control
• Stop or FIFO logging mode
• Immediate, delayed, or push-button logging activation
• Up to 10 years of battery life at a 1-minute sampling interval
• Rugged aluminum enclosure
• Conformal-coated PCB
• SiteView software support
• Remote Ethernet access through Smart-Hub
• RESTful Web API and Modbus TCP integration through Smart-Hub

Typical Applications

The LRTD is suitable for:

• Multi-point RTD temperature monitoring
• PT100 temperature logging
• PT500 temperature logging
• PT1000 temperature logging
• Laboratory testing
• Research and development
• Industrial process monitoring
• Environmental monitoring
• Equipment testing
• Product validation
• Long-term temperature recording

Documents

• SITE-LOG RTD Temperature Data Logger (LRTD) Specifications
• SiteView Specifications
• F.A.Q