Precision Sensing for Solar PV & Environment

Q: What does IEC 61724-1:2021 Class A compliance mean for these sensors?

IEC 61724-1:2021 defines performance criteria for solar photovoltaic system monitoring. Class A is the highest tier — it mandates the strictest measurement accuracy for module temperature, irradiance, and meteorological parameters. Sensors meeting Class A accuracy ±(0.15 + 0.0020|t|) ensure bankable yield data and are accepted by independent engineers for financial reporting.

Q: Which Rigel 2 variant should I choose — MT-A420, MT-RTD1K, or MT-RS485?

MT-A420 (4-20mA) suits legacy SCADA/PLC systems that accept standard analog current loops. MT-RTD1K (PT1000 resistive) is best when your data logger has a dedicated RTD input and you need the finest resolution (0.001°C) for research-grade accuracy. MT-RS485 (Modbus RTU) is ideal for modern digital networks, large-scale plants requiring multi-drop daisy chains, and systems already using RS485 communication.

Q: Can the Rigel 2 sensors be installed on bifacial PV modules without affecting their output?

Yes. The Rigel 2 series has a low-profile design (Ø25.4 mm × 7.2 mm) specifically engineered to minimise cell shading on bifacial modules. The self-adhesive high-strength mounting ensures secure attachment to module back sheets without mechanical fasteners or additional hardware.

Q: How does the ALT-TH110 differ from a standard temperature/humidity sensor?

The ALT-TH110 uses a stainless steel SS304/SS316 sintered porous filter housing that provides IP65 protection while maintaining excellent airflow to the sensing element. Its combined simultaneous T+RH measurement, RS485 Modbus RTU output, and IEC 61724-1:2021 Class A accuracy tolerance make it purpose-built for solar weather monitoring stations rather than general HVAC use.

Q: What cable lengths are supported for the Rigel 2 module sensors?

Standard cable length is 2 meters. For RS485 variants (MT-RS485), cable runs can be extended significantly — the RS485 protocol supports runs up to several hundred metres with appropriate cable selection. For 4-20mA variants (MT-A420), the current loop can also support long cable runs without signal degradation. Contact our engineering team for specific extended-length requirements.

Q: Are these sensors compatible with third-party data loggers and SCADA systems?

Yes. MT-A420 uses the industry-standard 4-20mA current loop accepted by virtually all PLCs, DAQ systems, and SCADA platforms. MT-RS485 and ALT-TH110 use Modbus RTU over RS485, supported by Ignition, WinCC, InTouch, Siemens, and all major industrial control systems. MT-RTD1K outputs a direct PT1000 resistance signal readable by any precision DAQ card with RTD inputs.

Q: What is the operating temperature range of the Rigel 2 sensors?

MT-A420 and MT-RTD1K are rated for -40°C to +150°C — matching the full thermal range of modern PV modules in both arctic and desert deployments. MT-RS485 is rated -40°C to +80°C (due to the ABS enclosure addition for the RS485 electronics). ALT-TH110 covers -40°C to 125°C for ambient air sensing.

Q: Do these sensors require factory calibration certificates?

Each Aeron sensor ships with a factory calibration certificate traceable to national standards. This documentation is required for IEC 61724-1:2021 Class A system verification and is accepted by independent engineers in yield assessment and lender reports. Recalibration intervals depend on application requirements — typically 1–2 years for bankable solar monitoring.

Aeron's Class A certified sensor lineup — the ALT-TH110 ambient sensor and Rigel 2 module temperature family — delivers high-fidelity thermal and humidity data compliant with IEC 61724-1:2021 for solar PV monitoring, agrivoltaic sites, and meteorological applications.

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4Sensor VariantsIn this family
Class AIEC AccuracyIEC 61724-1:2021
IP65Ingress ProtectionAll-weather rated
0.001°CBest ResolutionRIGEL 2 MT-RTD1K

Product Intelligence Dashboard

Select a sensor to explore specs, features, and applications in detail

Choose a sensorALT-TH110MT-A420MT-RTD1KMT-RS485

Class A · Environmental · ALT-TH110 · Product #52017

Air Temp & Humidity Sensor

Dual-Parameter Environmental Intelligence · IEC 61724-1:2021 · IP65 · RS485 MODBUS RTU · SS304/SS316

Stainless steel SS304/SS316 air temperature and relative humidity sensor with porous sintered filter — Class A per IEC 61724-1:2021. RS485 Modbus RTU output, IP65-rated for both indoor and outdoor renewable energy monitoring applications.

-40 to 125°CTemp Range
0 – 100% RHRH Range
±0.2°C maxTemp Uncertainty
±1% RH maxRH Uncertainty
0.01°C / 0.01% RHResolution

Output Signal	RS485 MODBUS RTU
Temp Range	-40°C to 125°C
Temp Uncertainty	±0.2°C (max)
Temp Resolution	0.01°C
RH Range	0% to 100% RH
RH Uncertainty	±1% RH
RH Resolution	0.01% RH
Power Supply	9V to 17V DC
IP Protection	IP65
Housing Material	SS304 / SS316
Filter Type	Porous sintered SS
Device Type	Probe
Standard	IEC 61724-1:2021
Product Code	52017

Features

Class A per IEC 61724-1:2021
Simultaneous T + RH measurement
Stainless Steel SS304/SS316 body
Porous sintered SS filter
Indoor & outdoor use
Optional UV radiation shield for outdoor
SCADA / BMS / HVAC compatible
Real-time RS485 MODBUS RTU output

Applications

Renewable Metrological Stations
Cold Chain Vehicle Monitoring
HVAC Systems
Environmental Research Stations

Download Datasheet

Gen 2 · Solar PV · RIGEL 2 MT-A420 · Product #55009

Module Temp Sensor 4-20mA

Analog Precision for PV Thermal Tracking · IEC 61724-1:2021 · IP65 · 4–20 mA Current · Aluminium 6082

Second-generation PT1000 module temperature sensor with industry-standard 4-20mA analog output. Compact anodized aluminum body with self-adhesive mount, optimised for both conventional and bifacial PV modules.

-40 to +150°CTemp Range
0.01°CResolution
±0.3°Uncertainty
0.5 mACurrent Consumption
<15 gmsWeight

Output Signal	4 to 20 mA Current
Temp Range	-40°C to +150°C
Accuracy	Class A ±(0.15 + 0.0020\|t\|)
Uncertainty	±0.3°
Resolution	0.01°C
Sensor Element	RTD PT1000 Class A
Current Consumption	0.5 mA
Supply Voltage	12VDC / 24VDC
Op. Temperature	-40°C to +150°C
IP Rating	IP65
Material	Aluminium 6082
Dimensions	Ø25.4 mm × Thickness 7.2 mm
Weight	<15 gms (excl. cable)
Cable Length	2 meters
Product Code	55009

Features

Class A accuracy ±(0.15 + 0.0020|t|)
Industry-standard 4-20mA analog output
Bifacial PV module optimised
Low-profile — minimises shadowing
Self-adhesive high-strength mount
Anodized Aluminium 6082 body
Corrosion-resistant enclosure
Ultra-low 0.5 mA current consumption

Applications

Solar PV Module Temperature Monitoring
Surface Temperature Monitoring
Performance Ratio Calculation
SCADA / PLC Integration

Download Datasheet

Gen 2 · Solar PV · RIGEL 2 MT-RTD1K · Product #55006

Module Temp Sensor PT1000

Resistive Output — Highest Resolution · IEC 61724-1:2021 · IP65 · Resistive PT1000 · Aluminium 6082

Second-generation PT1000 module temperature sensor delivering direct resistive output — the finest resolution in the Rigel 2 family at 0.001°C. Ideal for research-grade and high-accuracy thermal analysis applications.

-40 to +150°CTemp Range
0.001°CResolution
Class AAccuracy
-40 to +150°COp. Temp
<15 gmsWeight

Output Signal	Resistance Output (PT1000)
Temp Range	-40°C to +150°C
Accuracy	Class A ±(0.15 + 0.0020\|t\|)
Resolution	0.001°C
Sensor Element	RTD PT1000 Class A
Op. Temperature	-40°C to +150°C
IP Rating	IP65
Material	Aluminium 6082
Dimensions	Ø25.4 mm × Thickness 7.2 mm
Weight	<15 gms (excl. cable)
Cable Length	2 meters
Power	Passive (no supply required)
Product Code	55006

Features

Class A accuracy ±(0.15 + 0.0020|t|)
0.001°C ultra-fine resolution — 10× finer than siblings
Direct resistive PT1000 passive output
Bifacial PV module optimised
Low-profile — minimises shadowing
Self-adhesive high-strength mount
Anodized Aluminium 6082 body
No external power needed (passive)

Applications

Solar PV Module Temperature Monitoring
Surface Temperature Monitoring
Research-Grade Thermal Analysis
High-Precision Data Acquisition

Download Datasheet

Gen 2 · Solar PV · RIGEL 2 MT-RS485 · Product #55020

Module Temp Sensor RS485

Digital Modbus — Ready for Smart Grids · IEC 61724-1:2021 · IP65 · RS485 MODBUS RTU · Al 6082 / ABS

Second-generation PT1000 module temperature sensor with RS485 Modbus RTU digital output. Enables multi-drop daisy-chaining for large-scale solar plants and seamless SCADA integration.

-40 to +150°CTemp Range
0.01°CResolution
±0.3°Uncertainty
-40 to +80°COp. Temp
<20 gmsWeight

Output Signal	RS485 MODBUS RTU
Temp Range	-40°C to +150°C
Accuracy	Class A ±(0.15 + 0.0020\|t\|)
Uncertainty	±0.3°
Resolution	0.01°C
Sensor Element	RTD PT1000 Class A
Supply Voltage	12VDC / 24VDC
Op. Temperature	-40°C to +80°C
IP Rating	IP65
Material	Aluminium 6082 / ABS
Dimensions	Ø25.4 mm × Thickness 7.2 mm
Weight	<20 gms (excl. cable)
Cable	Li2YD11Y-24 AWG BRD
Product Code	55020

Features

Class A accuracy ±(0.15 + 0.0020|t|)
RS485 Modbus RTU digital output
Multi-drop daisy-chain capable
Bifacial PV module optimised
Low-profile — minimises shadowing
Al 6082 + ABS hybrid enclosure
8-wire industrial cable harness
Industry-standard SCADA integration

Applications

Solar PV Module Temperature Monitoring
Surface Temperature Monitoring
Large-Scale PV Plant SCADA
Multi-Sensor Daisy-Chain Networks

Download Datasheet

Compare All Sensor Variants

MT-A420, MT-RTD1K & MT-RS485 — every spec, side by side.

Sensing Technology
	MT-A420Module Temp · 4-20mA	MT-RTD1KModule Temp · PT1000	MT-RS485Module Temp · RS485
Show only the differences
Sensor Type	PT1000 RTD Module	PT1000 RTD Module	PT1000 RTD Module
Temp Range	-40°C to +150°C	-40°C to +150°C	-40°C to +150°C
Sensor Element	RTD PT1000 Class A	RTD PT1000 Class A	RTD PT1000 Class A
Accuracy & Resolution
Temp AccuracyIEC 60751 Class A — tightest standard for PT1000	Class A ±(0.15 + 0.002\|t\|)	Class A ±(0.15 + 0.002\|t\|)	Class A ±(0.15 + 0.002\|t\|)
Temp Uncertainty	±0.3°	—	±0.3°
Temp ResolutionMT-RTD1K: 10× finer resolution than siblings	0.01°C	0.001°C (stronger)	0.01°C
Output & Electrical
Output Signal	4–20 mA Current loop	PT1000 Resistive	RS485 Modbus RTU
Supply VoltageMT-RTD1K: passive — no power supply needed	12 / 24 V DC	Passive (none) (stronger)	12 / 24 V DC
Multi-drop	—	—	Yes daisy-chain capable (stronger)
Current Draw	0.5 mA	0 mA (passive)	—
Physical & Ingress
IP Rating	IP65	IP65	IP65
Operating TempMT-A420 & MT-RTD1K: widest thermal range	-40°C to +150°C (stronger)	-40°C to +150°C	-40°C to +80°C
Body Material	Aluminium 6082 (anodized)	Aluminium 6082 (anodized)	Al 6082 / ABS hybrid
Dimensions	Ø25.4 × 7.2 mm	Ø25.4 × 7.2 mm	Ø25.4 × 7.2 mm
Weight	<15 gms	<15 gms	<20 gms
Mount Style	Self-adhesive high-strength	Self-adhesive high-strength	Self-adhesive high-strength
Standards & Application
IEC Standard	IEC 61724-1:2021 Class A	IEC 61724-1:2021 Class A	IEC 61724-1:2021 Class A
Primary Use	PV Module Temp Solar plants	PV Module Temp Research grade	PV Module Temp Large SCADA
Bifacial PV Ready	Yes	Yes	Yes
SCADA / BMS	4-20mA loop compatible	PT1000 DAQ compatible	RS485 Modbus compatible
Cable Length	2 meters	2 meters	2 meters
Product Code	55009	55006	55020
Download datasheet	Datasheet ↓	Datasheet ↓	Datasheet ↓

Technology Deep Dive

The engineering behind Class A sensing

Class A precision at every point
PT1000 RTD Sensing Element
All Rigel 2 module temperature sensors are built around a Class A PT1000 resistance temperature detector. PT1000 offers 10× higher resistance than PT100, dramatically reducing the sensitivity to lead resistance — critical for long cable runs in large-scale solar plants. Class A tolerance ±(0.15 + 0.0020|t|) ensures accuracy is maintained from -40°C to +150°C without field recalibration.
- PT1000 Class A
- 10× less lead error
- -40 to +150°C
- Long cable runs
Minimal shading — maximum accuracy
Low-Profile Thermal Contact
The Rigel 2 body is machined to Ø25.4 mm × 7.2 mm — one of the smallest footprints available for a calibrated module temperature sensor. The self-adhesive high-strength mount creates intimate thermal contact with the module back sheet, eliminating air gap errors. Low profile minimises cell shading on bifacial modules where rear-side irradiance contributes up to 25% of energy yield.
- Ø25.4 mm × 7.2 mm
- Self-adhesive
- Bifacial safe
- Zero air gap
Three output options, one platform
Protocol Intelligence
Aeron's Rigel 2 family offers three signal protocols — 4-20mA (noise-immune analog, ideal for legacy PLCs), PT1000 resistive (passive, highest resolution at 0.001°C for precision DAQ), and RS485 Modbus RTU (digital, multi-drop up to 32 nodes per bus, long cable runs). Choose the interface that matches your existing infrastructure without compromising sensor accuracy.
- 4-20mA analog
- RS485 Modbus RTU
- PT1000 passive
- 32-node daisy chain

IEC61724

IEC 61724-1:2021 — What Class A Means

IEC 61724-1:2021 is the international standard for photovoltaic system performance monitoring. Class A is the highest tier, demanding temperature measurement accuracy of ±(0.15 + 0.0020|t|) °C — where |t| is the absolute temperature value in °C. This tolerance ensures that module temperature data used in performance ratio calculations, energy yield reports, and bankability assessments meets the most stringent requirements accepted by independent engineers and financial institutions.

Class A Accuracy
Bankable Data
IEC Compliant

Built for Every Environment

From utility-scale solar farms to precision research laboratories

Module Temperature Monitoring
Utility-Scale Solar PV
Monitor back-of-module temperatures across string zones to calculate Performance Ratio, validate thermal limits, and feed IEC-compliant yield reports for utility-scale solar assets.
Recommended
- MT-A420
- MT-RTD1K
- MT-RS485
Meteorological Mast Sensing
Solar Weather Stations
Precision ambient temperature and humidity sensing for IEC 61724-1:2021 compliant solar weather monitoring stations — feeding irradiance and environmental data to cloud analytics.
Recommended
- ALT-TH110
- MT-RS485
Dual Land-Use Monitoring
Agrivoltaic Installations
Dual-purpose sensing for agrivoltaic installations — module temperature monitoring for PV yield alongside ambient T+RH for crop microclimate management.
Recommended
- ALT-TH110
- MT-A420
Process & Building Automation
Industrial SCADA / BMS
RS485 Modbus RTU and 4-20mA outputs enable plug-and-play integration with industrial SCADA, DCS, PLC, and Building Management Systems.
Recommended
- ALT-TH110
- MT-A420
- MT-RS485
Vehicle & Warehouse Monitoring
Cold Chain Logistics
Continuous temperature and humidity monitoring across refrigerated vehicles and warehouses — reliable data logging with RS485 Modbus RTU output for compliance reporting.
Recommended
- ALT-TH110
High-Precision Thermal Analysis
Research & Testing Labs
The MT-RTD1K's 0.001°C resolution makes it ideal for academic research, module certification testing, and precision thermal characterisation work.
Recommended
- MT-RTD1K

Seamless System Compatibility

All sensors in the Aeron weather sensor lineup use industry-standard communication protocols — RS485 Modbus RTU and 4-20mA — ensuring plug-and-play compatibility with the widest possible range of data acquisition and monitoring infrastructure.

Aeron Ace Data LoggersXtreme XG920/XG930 · DLG80 — native compatibility, IEC Class A end-to-end
SCADA / DCS SystemsModbus RTU protocol supported by all major SCADA platforms including Ignition, WinCC, InTouch
PLC / RTU Controllers4-20mA analog loop and RS485 ports available on virtually all industrial controllers
Building Management SystemsDirect BMS integration for HVAC temperature and humidity monitoring via RS485 Modbus
Data Acquisition SystemsPT1000 RTD inputs available on precision DAQ cards from NI, Yokogawa, Hioki, and more

Frequently Asked Questions

Everything you need to know about Aeron's weather sensor and module temperature sensor lineup.

What does IEC 61724-1:2021 Class A compliance mean for these sensors?

IEC 61724-1:2021 defines performance criteria for solar photovoltaic system monitoring. Class A is the highest tier — it mandates the strictest measurement accuracy for module temperature, irradiance, and meteorological parameters. Sensors meeting Class A accuracy ±(0.15 + 0.0020|t|) ensure bankable yield data and are accepted by independent engineers for financial reporting.

Which Rigel 2 variant should I choose — MT-A420, MT-RTD1K, or MT-RS485?

MT-A420 (4-20mA) suits legacy SCADA/PLC systems that accept standard analog current loops. MT-RTD1K (PT1000 resistive) is best when your data logger has a dedicated RTD input and you need the finest resolution (0.001°C) for research-grade accuracy. MT-RS485 (Modbus RTU) is ideal for modern digital networks, large-scale plants requiring multi-drop daisy chains, and systems already using RS485 communication.

Can the Rigel 2 sensors be installed on bifacial PV modules without affecting their output?

Yes. The Rigel 2 series has a low-profile design (Ø25.4 mm × 7.2 mm) specifically engineered to minimise cell shading on bifacial modules. The self-adhesive high-strength mounting ensures secure attachment to module back sheets without mechanical fasteners or additional hardware.

How does the ALT-TH110 differ from a standard temperature/humidity sensor?

The ALT-TH110 uses a stainless steel SS304/SS316 sintered porous filter housing that provides IP65 protection while maintaining excellent airflow to the sensing element. Its combined simultaneous T+RH measurement, RS485 Modbus RTU output, and IEC 61724-1:2021 Class A accuracy tolerance make it purpose-built for solar weather monitoring stations rather than general HVAC use.

What cable lengths are supported for the Rigel 2 module sensors?

Standard cable length is 2 meters. For RS485 variants (MT-RS485), cable runs can be extended significantly — the RS485 protocol supports runs up to several hundred metres with appropriate cable selection. For 4-20mA variants (MT-A420), the current loop can also support long cable runs without signal degradation. Contact our engineering team for specific extended-length requirements.

Are these sensors compatible with third-party data loggers and SCADA systems?

Yes. MT-A420 uses the industry-standard 4-20mA current loop accepted by virtually all PLCs, DAQ systems, and SCADA platforms. MT-RS485 and ALT-TH110 use Modbus RTU over RS485, supported by Ignition, WinCC, InTouch, Siemens, and all major industrial control systems. MT-RTD1K outputs a direct PT1000 resistance signal readable by any precision DAQ card with RTD inputs.

What is the operating temperature range of the Rigel 2 sensors?

MT-A420 and MT-RTD1K are rated for -40°C to +150°C — matching the full thermal range of modern PV modules in both arctic and desert deployments. MT-RS485 is rated -40°C to +80°C (due to the ABS enclosure addition for the RS485 electronics). ALT-TH110 covers -40°C to 125°C for ambient air sensing.

Do these sensors require factory calibration certificates?

Each Aeron sensor ships with a factory calibration certificate traceable to national standards. This documentation is required for IEC 61724-1:2021 Class A system verification and is accepted by independent engineers in yield assessment and lender reports. Recalibration intervals depend on application requirements — typically 1–2 years for bankable solar monitoring.

Contact

Ask for a price, or talk to one of our engineers about your platform or your plant.

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support@aeronsystems.com +91 91686 13672
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Jobs and applications
hr@aeronsystems.com +91 95884 95304

Offices

India

Head office and design centre, Pune

Plot No. 7, Lane No. 5, Laxman Nagar, Balewadi
Pune, Maharashtra 411045, India

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Factory, Pune

Vivan Kohli Industrial Park, Shed No. 5, Gat No. 446
Old Pune-Mumbai Highway, Naigaon, Kanhe Phata, Talegaon
Pune, Maharashtra 412106, India

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Sales and support, Bengaluru

First Floor, Building No. 11, Sai Anugraha
Jeevan Bhima Nagar Main Road
Bengaluru, Karnataka 560075, India

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Sales and support, Vijayawada

Door No. 52-1/4-8D, Plot No. 9, 5th Cross Road
Veterinary Colony
Vijayawada, Andhra Pradesh 520008, India

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International

Aeron Systems Pvt. Ltd., Sharjah

Saif Executive Office # P8-17-02
Sharjah Airport International Free Zone Authority
PO Box 8000, Sharjah, U.A.E.

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Precision Sensing for Solar PV & Environment

Product Intelligence Dashboard

Air Temp & Humidity Sensor

Features

Applications

Module Temp Sensor 4-20mA

Features

Applications

Module Temp Sensor PT1000

Features

Applications

Module Temp Sensor RS485

Features

Applications

Compare All Sensor Variants

Technology Deep Dive

PT1000 RTD Sensing Element

Low-Profile Thermal Contact

Protocol Intelligence

IEC 61724-1:2021 — What Class A Means

Built for Every Environment

Utility-Scale Solar PV

Solar Weather Stations

Agrivoltaic Installations

Industrial SCADA / BMS

Cold Chain Logistics

Research & Testing Labs

Seamless System Compatibility

Frequently Asked Questions

Contact

Offices

Head office and design centre, Pune

Factory, Pune

Sales and support, Bengaluru

Sales and support, Vijayawada

Aeron Systems Pvt. Ltd., Sharjah