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Environmental measurement & analysis
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STR-21G-S system

STR-21G-S system

Features

  • All-in-one Solar Monitoring System 
  • Top class and fast reponse sensors
  • Analogue, 4-20mA, Modbus sensor outputs
  • Combine with any Data Acquisition System
  • Low power DC and AC operation

 

EKO’s new solar Monitoring System, called STR-21G-S, is a dedicated sensor system to perform the most accurate solar radiation measurements of the three solar radiation components (Direct, Diffuse and Global). It can be easily integrated to any DAQ system, which has multiple analog or digital inputs. With the standard sun-position sensor and GPS receiver built inside the sun tracker the system set-up will be quick and easy. 

The system is based on the STR-21G Sun tracker with a new shading disk assembly which can be mounted on one arm of the tracker. In combination with the new generation MS-80 Secondary standard pyranometer and MS-56 First class pyrheliometer it makes it the most "high end" sensor system for solar energy research.  

The STR-21G-S system can be freely configured to measure the required Solar radiation components in the most accurate way. Hence a cost effective solution can be created for every application. In harsh climate environments, the MV-01 ventilator & heater can be deployed. The MS-56 pyrheliometer has a heated front window to avoid condensation and ice which can affect the measurements.

Global radiation can be composed by the sum of the cosine weighted direct and diffuse. This way the sun tracker with pyrheliometer and shaded pyranometer can provide all three Solar radiation components. Unique to the system, EKO’s radiometers have the ability to sample much faster than traditional solar sensors. Faster sample rates allow the sensor to ‘catch’ more accurately the peak irradiance value under variable atmospheric conditions and lower the measurement uncertainty of one minute averaged values. 

 

Specifications

STR-21G-S system can be freely configured. The diagram below summarizes the possible options for composition of the solar monitoring station, based on application and desired parameters.

System configuration

STR-21G-S (DNI) STR-21G Sun Tracker
  MS-56 First Class Pyrheliometer
   
STR-21G-S1 (DNI + GHD) STR-21G Sun Tracker
  MS-80 Top mounting plate (Single position)
  Shading disk assembly 
  MS-56 First Class Pyrheliometer
  MS-80 Secondary standard Pyranometer
  MV-01 Ventilator & Heater (optional)
   
STR-21G-S2 (DNI + GHD + GHI) STR-21G Sun Tracker
  MS-80 Top mounting plate (Double position)
  Shading disk assembly 
  MS-56 First Class Pyrheliometer
  MS-80 Secondary standard Pyranometer (Diffuse)
  MS-80 Secondary standard Pyranometer (Global)
  MV-01 Ventilator & Heater (optional)

 

 

Specifications (typical)
STR-21G Sun Tracker
Driving technology
Harmonic Drive / Single arm
Pointing accuracy
< 0.01°
Tracking mode
Sun-sensor mode and Calculation mode
Sun-sensor field of view
+/- 15°
GPS 
Location and time 
LED Indicator
Power, GPS status
Environmental Protection
IP65
Temperature range
-40~+50℃ (-30 ~ +50℃ at cold start)
Communication
RS-232C, 9600bps, 8N1
Power requirement

DC21 to 32V, 20W for DC (Power consumption <10W)

AC100 to 240V, 50/60Hz, (20W external Power adapater)

Dimension
430(W) x 380(D) x 440(H) mm
Weight
14.5 kg

 

 

Specifications (typical) MS-56 Pyrheliometer
ISO 9060 classification First Class
Response time 95% < 1 s
Zero offset - Temperature change (5K/hr) < 1 W/m²
Non-stability (change/year) < 0.5 %
Non-linearity (100 -1000W/m²) < 0.5 %
Spectral selectivity (0.35-1.5µm) < 1 %
Temp. dependency (-20°C to 50ºC / @ 20°C) < 0.5 %
Tilt response (at 1000W/m²) < 0.2 %
Sensitivity (µV/W/m²) Approx. 10
Impedance (Ω) Approx. 5000
Operating temperature range (°C) - 40 to +80
Cable length 10m
Spectral range (> 50% transmittance) 200 to 4000 nm

  

Specifications (typical)

MS-80

MS-80A

 MS-80M

Output

mV

4-20mA

MODBUS

ISO 9060 classification

Secondary

Standard

Secondary

Standard

Secondary

Standard

Response time 95% (sec)

< 0.5

 < 1.5

 < 1

Zero offset 

- Thermal radiation (200W/m²)

< 1 W/m²

 < 1 W/m²

 < 1 W/m²

 Zero offset 

- Temperature change (5K/hr)

+/- 1 W/m²

 +/- 1 W/m²

 +/- 1 W/m²

Non-stability (change/5 years)

+/- 0.5 %

 +/- 0.5 %

  +/- 0.5 %

Non-linearity (at 1000W/m²)

+/- 0.2 %

 +/- 0.2 %

 +/- 0.2 %

Directional response

(at 1000W/m²)

< 10 W/m²

 < 10 W/m²

  < 10 W/m²

Spectral selectivity (0.35-1.5µm)

+/- 3 %

 +/- 3 %

  +/- 3 %

Temp. response (for 70°C band)

< 1 %

 < 0.4 %

  < 0.4 %

Tilt response (at 1000W/m²)

+/- 0.2 %

 +/- 0.2 %

 +/- 0.2 %

Sensitivity (µV/W/m²)

Approx. 10

 1mA / 100 W/m2

 -

Impedance (Ω)

Approx. 45kΩ

 -

  -

Operating temperature range (°C)

- 40 to +80

 - 40 to +80

 - 40 to +80 

Irradiance range (W/m²)

0 - 4000

0 - 4000

0 - 4000

Cable length

10m

 10m

 10m

Wavelength range in nm

285 to 3000

 285 to 3000

 285 to 3000

Ingress protection 

IP 67

IP 67

IP 67

  

Specification (typical)

MV-01

Compatible sensors

MS-80, MS-80A, MS-80M

Operating Voltage

DC 12V +/- 10%

Power consumption

Fan (2W) / Heater (7W)

Temperatre incerase of glass dome

< 0.25℃ (fan) / > 1℃ (fan + heater) 

Induced Zero offsets

 2

Tacho output

Pulse / 100Hz / 3000 RPM

Environmental protection

IP 54

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