Cave Environmental Monitoring System

Ethernet-based monitoring of temperature, humidity, CO2, wind direction, and wind speed at multiple points inside a cave.

PnP IoTs configured and installed a distributed sensing system that collects cave environmental data from six locations and uploads it to a server through a fixed-IP Ethernet network.

RTUs and environmental sensor interfaces prepared and verified before field installation.

Project Overview

The customer needed continuous environmental monitoring at distributed locations inside a cave. Six points required temperature, humidity, and CO2 measurement, while three of those points also required wind direction and wind speed measurement.

A key integration requirement was compatibility with HD52.3D147 wind instruments that were already selected for the site. PnP IoTs adapted the interface and added a 5 V to 24 V converter because the wind instruments required a 24 V supply.

Customer Requirements

  • Monitor temperature, humidity, and CO2 at six cave locations.
  • Monitor wind direction and wind speed at three locations.
  • Connect every RTU through Ethernet using a fixed IP address.
  • Upload measured data to the customer’s server.
  • Reuse and integrate the specified wind instruments.

PnP IoTs Solution

PnP IoTs surveyed the site, adapted the wind instrument interface, assembled six RTU sets, performed sensor aging and office verification, and completed the field installation and server upload test.

System Configuration

Item Configuration Role
RTU PD-AMS-S8 x 6 Collects sensor data and transfers it to the server over Ethernet.
Temperature / Humidity / CO2 Module FC0-TMHMCO2 x 6
(including AD0-TMHMCO2 x 6)		 Measures the cave’s temperature, relative humidity, and CO2 concentration.
Wind Instrument Interface EB0-PLC232 x 3
Later designated SB0-HD523D147		 Connects the HD52.3D147 wind direction and wind speed instruments to the RTU system.
Power Conversion 5 V to 24 V converter x 3 Supplies the voltage required by the wind instruments.
Communication Fixed-IP Ethernet Uploads data from each installation point to the server.
PC Software AutoSave Automatically receives and stores monitoring data.

Engineering and Verification

  1. The installation team surveyed the cave and confirmed the six sensor locations.
  2. The existing wind instruments were removed temporarily for interface compatibility testing.
  3. PnP IoTs modified the connection method and added 5 V to 24 V power conversion.
  4. All temperature, humidity, CO2, wind direction, and wind speed channels were aged and checked in the office.
  5. Six complete RTU sets were assembled before delivery to reduce field work and installation risk.

Field Installation

Four technicians completed the cave installation in approximately six hours. The network infrastructure had already been installed, so each Ethernet cable was connected to its RTU and tested using the assigned fixed IP address.

During commissioning, the team confirmed that data from the cave sensors was uploaded correctly to the server. The cave temperature was approximately 14 to 16°C during the work.

Completed field installation and communication verification inside the cave.

System Flow

  1. Environmental sensors measure temperature, humidity, and CO2 at six points.
  2. HD52.3D147 instruments measure wind direction and wind speed at three points.
  3. Each PD-AMS-S8 RTU collects its connected sensor values.
  4. Fixed-IP Ethernet communication transfers data from the cave to the server.
  5. AutoSave receives and stores the collected values for monitoring and analysis.

Operational Benefits

  • One system monitors both cave air quality and airflow conditions.
  • Distributed RTUs provide measurements from multiple locations rather than a single reference point.
  • Ethernet and fixed IP addressing simplify server integration and device identification.
  • Compatibility engineering allows specialized or existing instruments to be incorporated into the IoT system.
  • Automatic storage replaces manual measurements and supports trend analysis.

Applicable Sites

  • Natural and tourist caves
  • Underground cultural and storage facilities
  • Tunnels and underground work areas
  • Mines and enclosed industrial spaces
  • Sites requiring distributed air-quality and airflow monitoring
Sales Message: This case demonstrates PnP IoTs’ ability to combine environmental sensors, specialized wind instruments, distributed RTUs, Ethernet communication, and automatic data storage into a field-ready monitoring system for challenging underground environments.

Source: Preparation and system verification / Field installation and commissioning