The PRECISE-LOG PL-H is an 8-channel, battery-powered, standalone thermistor and resistance data logger designed for industrial, laboratory, research, testing, and long-term temperature-monitoring applications.

The logger provides:

• 8 external thermistor / resistance input channels
• 16-bit measurement resolution
• USB communication
• 8 MB non-volatile flash memory
• Long-term standalone operation

PL-H is optimized for temperature measurement using compatible thermistors, including commonly used 10 kΩ NTC thermistors.

Each channel can be independently enabled and configured through SiteView.

The PL-H is the non-WiFi version of the PRECISE-LOG thermistor platform and is well suited to applications requiring standalone recording, direct USB communication, or network access through Smart-Hub. 

Multi-Channel Thermistor and Resistance Measurement

The PL-H provides eight external input channels for simultaneous thermistor or resistance measurement.

It is well suited to multi-point temperature-monitoring applications using compatible NTC thermistors.

For a 10 kΩ NTC thermistor, the published logger accuracy is:

±0.2°C from 0°C to 70°C

This value does not include the accuracy of the thermistor probe itself. 

The PL-H can also provide resistance readings, allowing compatible resistive sensors to be used with appropriate SiteView equations or calibration.

High-Resolution Data Logging

The PL-H uses a 16-bit analog-to-digital converter with a measurement resolution of:

0.0018%

This provides high-resolution thermistor and resistance measurements for laboratory, industrial, research, validation, and testing applications.

Standalone Operation and Long-Term Recording

The PL-H operates independently after configuration and stores measurements in 8 MB of non-volatile flash memory.

The memory provides storage for approximately 4 million readings and retains recorded data for more than 20 years. 

Logging can be configured for:

• Immediate start
• Delayed start
• Field push-button activation

When memory becomes full, the logger can either:

• Stop recording, or
• Continue recording in FIFO mode

The built-in 3.6 V lithium battery provides up to approximately 10 years of operation at a 1-minute sampling interval in standalone mode, depending on operating conditions and configuration. 

USB Communication and SiteView Software

The PL-H connects directly to a Windows PC through its Plug & Play USB interface.

SiteView software provides tools for:

• Configuring thermistor / resistance channels
• Configuring logging sessions
• Downloading recorded data
• Viewing real-time temperatures or resistance values
• Displaying graphs and tables
• Configuring alarm thresholds
• Applying custom calibration
• Applying custom equations
• Converting resistance measurements into engineering units
• Exporting and analyzing recorded data

For local operation, SiteView communicates directly with the PL-H through USB.

For network applications, the PL-H can be connected to a Smart-Hub and accessed remotely by supported Microedge software.

Alarm Functions

The PL-H provides configurable alarm functions for temperature- and resistance-monitoring applications.

Each channel supports two programmable alarm thresholds.

The onboard tri-color status LED provides visual indication of:

• Normal sampling
• Alarm condition
• Low battery

The LED can be disabled to reduce power consumption. 

Remote Access and Network Integration

Although the PL-H 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 acts as a communication gateway and allows connected USB data loggers to be accessed through:

• SiteView
• SiteView-Web
• SiteView SDK
• Pluto

Smart-Hub also provides:

• RESTful Web API
• Modbus TCP Gateway

This allows PL-H thermistor and resistance data to be integrated with third-party software, PLCs, HMIs, SCADA systems, and other industrial monitoring platforms.

Unlike the PL-HW, the PL-H does not contain a built-in WiFi interface and does not operate directly as a Modbus TCP server. Network, RESTful API, and Modbus TCP access for PL-H are provided through Smart-Hub.

Rugged Industrial Design

The PL-H is housed in a durable aluminum enclosure designed for laboratory, industrial, and field applications.

Its operating environment is:

−40°C to +70°C (−40°F to +158°F)

and:

0–95% RH, non-condensing. 

KEY FEATURES

• 8 External Thermistor / Resistance Channels
  Provides multi-point measurement using independently configurable external inputs.

• 10 kΩ NTC Thermistor Support
  Optimized for temperature measurement with compatible 10 kΩ NTC thermistors.

• Resistance Measurement
  Supports resistance-based measurement for compatible resistive sensors and custom equations.

• 16-Bit Data Resolution
  Provides 0.0018% measurement resolution.

• 8 MB Non-Volatile Flash Memory
  Stores approximately 4 million readings for long-term standalone recording.

• 1 Second to 12 Hour Sampling
  Wide programmable sampling interval selection for short-term testing and long-term monitoring.

• Long Battery Life
  Up to approximately 10 years at a 1-minute sampling interval in standalone operation.

• USB Communication
  Provides direct local communication with SiteView.

• SiteView Software Support
  Provides logger configuration, data download, real-time monitoring, plotting, calibration, custom equations, alarms, and data analysis.

• Programmable Alarm Thresholds
  Two configurable alarm thresholds are available for each channel.

• Flexible Logging Modes
  Supports immediate start, delayed start, field push-button activation, stop-on-full, and FIFO operation.

• Remote Network Access through Smart-Hub
  Smart-Hub provides Ethernet access for SiteView, SiteView-Web, SiteView SDK, and Pluto.

• RESTful Web API Integration
  Through Smart-Hub, PL-H data can be accessed by compatible third-party software.

• Modbus TCP Gateway Integration
  Smart-Hub can expose connected PL-H data through Modbus TCP for integration with PLCs, HMIs, SCADA systems, and other Modbus TCP masters.

• Rugged Aluminum Enclosure

  
  

TYPICAL APPLICATIONS

The PL-H is suitable for:

• Multi-point temperature monitoring
• 10 kΩ NTC thermistor monitoring
• Industrial process temperature monitoring
• Laboratory testing
• Research
• Product validation
• Environmental chambers
• HVAC monitoring
• Equipment temperature monitoring
• Manufacturing processes
• Resistance measurement
• Long-term unattended temperature logging
• Remote temperature monitoring through Smart-Hub
• PLC / SCADA temperature monitoring through Smart-Hub

DOCUMENTS

• PRECISE-LOG PL-H Thermistor Data Logger Specifications
• SiteView Specifications