MS-80 Secondary Standard Pyranometer “High-end for an industrial application”
EKO Instruments Co., Ltd.
K. Hoogendijk / W. Beuttell / A. Akiyama
EKO’s new generation ISO 9060 Secondary Standard sensor broke with thetradition of common pyranometer architecture and performance standards. The
innovative design inspired by the latest detector and Quartz diffusor technologies
enabling a breakthrough in unprecedented low thermal offset behaviour and fast
thermopile response. The MS-80, ISO 9060 Secondary standard pyranometer
developed for long term unattended outdoor operation to provide the lowest
measurement uncertainties and best data availability under all atmosphericconditions when deployed in harsh environments.

High-end for industrial application
To obtain the most reliable Solar irradiance data at PV plants or meteorologicalstations, ISO 9060 Secondary Standard pyranometers are most commonly prescribed.
These applications represent the beginning of the “high-end” applications forpyranometers. There are a variety of pyranometers in this category, some just comply
with the ISO 9060 requirements and defined as an acceptable standard for PV
monitoring applications. However, the best performing Secondary Standard
pyranometers in this “high-end” range of pyranometers are rare and only used for very
“high-end” research applications. The reason for their scarcity is their price is costprohibitive for many applications.
Our aim was to develop an industrial sensor at a price that would allow for distributive
networks while still realizing “high-end” specifications. This proliferation of “high-end”
sensors will improve data quality and accuracy for regular PV monitoring applications
and meteorological sensor networks. EKO’s approach has resulted in a new generation
secondary standard pyranometer, which provide the lowest measurement uncertainty.
Better performance combined with an extended warranty and re-calibration interval
period yield the lowest cost of ownership pyranometer on the market.

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EKO Instruments Co., Ltd.

	
  

	
  

The advantage of a lower measurement uncertainty
What does a lower measurement uncertainty mean on a short or long time scale?
Discerning short-term trends can only be detected with pyranometers capable ofproviding quality short-term data. Slower sensors cause longer time intervals between
measurements. Larger measurement uncertainties decrease confidence in the claims
made from the data. Confidence can be increased by applying statistics on an
increasingly large data set. However, this dataset takes time to accrue. If important
decisions must be made based on data taken over a short interval, a sensor with a fast
response time, low measurement uncertainty, and a matching data-acquisition system
are required.
One minute mean data values
Secondarystandard

First class

Second
class

	
  

	
  

Uncertainty

High end

Trend analysis period

Pyranometers with a slower response and greater measurement uncertainty can only
be used to detect long-term trends, perhaps taking weeks or even months. As themeasurement campaign continues for months or years, other important factors to take
into account come into play. A primary consideration for such long-term applications
require considerations of the long-term stability properties of a pyranometer. For PV
monitoring applications, it is beneficial to detect short-term changes to maintain andguarantee PV system performance. To detect PV system performance changes of forexample 2%, only pyranometers with a lower than 2% measurement uncertainty should
be used. In case a pyranometer or reference sensor is applied with a greatermeasurement uncertainty, it will take more time and data to detect system performancelosses.
Unique pyranometer architecture
Typical for the Secondary Standard thermopile pyranometers are the double domes,
which are applied to improve the thermal balance of the sensor and to lower the offset
characteristics. The “High-end” pyranometers have domes made of expensive Quartz or
Sapphire to reduce the offset uncertainty and are most commonly used for top
research specific applications. While the compact MS-80 sensor has only a single glassdome, through clever optical design it is immune to thermal offsets. Meaning, theperformance of the MS-80 rivals the top competition while sold at a fraction of the cost.
Without a second dome, the optics were designed to provide a true cosine response
and flat spectral responsivity in the range 285nm – 3000nm. Furthermore, the isolated
thermopile detector is hermetically sealed and accommodated deep inside the sensor
body to keep it thermally balanced. The long-term detector responsivity is enhanced
and is no longer affected by long-term exposure to UV irradiance, humidity, andpressure fluctuations. As a final plus, there is no longer the drying cartridge that needs
to be checked regularly. The MS-80 contains the drying agent inside the sealed sensor
body. There is no need for replacement.

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EKO Instruments Co., Ltd.

	
  

	
  

Outstanding performance
EKO Instruments’ test facilities are state of the art. Extensive indoor and outdoor tests
were carried out to validate MS-80 sensor performance characteristics and to quantify
the results. Specifications defined under ISO 9060 were verified primarily indoors.
Whereas outdoor tests were performed to assess the measurement performance anduncertainty compared against competing secondary pyranometers. In addition thelong-term stability characteristics were validated by independent test labs andresearch institutes.
The sensor characteristics and test results prove that the MS-80 sensor is not like anyother traditional secondary standard pyranometers in the market. Test results appeared
to be very consistent, given that traditional pyranometers generally have lessconsistency due to the detector construction and manufacturing process.
Specifications:Characteristics

ISO 9060 Secondary standard

MS-80

Response Time (95%)<0.5 Sec15 Sec

Zero Off-Set A (200W/m IR)

1 W/m2

7 W/m 2

Zero Off-Set B (5 K/h)

1 W/m 2

2 W/m 2

0.5 % (5 years)

0.8 %

0.2 %

0.5 %

2

Long-Term Stability (1 year)
Non-Linearity
Directional Response10 W/m

2

10 W/m 2

Spectral Selectivity (300nm – 1,5µm)

3 %

3 %

Temperature Response (-20 to 50ºC)1 %2 % (-10 to 40ºC)

Tilt Response
Wavelength range

0.2 %

0.5 %

285 to 3000 nm

300 - 3000 nm

Test results
EKO sensors were extensively tested indoors and outdoors during and after thedevelopment process. The performance characteristics are based on the typical values
as measured by multiple sensors.
Fastest detector response
The MS-80 has an analog thermopile providing a response time, which is only a fractionof second (99%). A fast detector is beneficial to stay perfectly in sync with rapid
atmospheric changes. Data can be sampled at a higher frequency to minimize themeasurement uncertainty for one minute or longer averaged values.
MS-80 Response time
MS-80 SN: PP001

MS-80 SN: PP003

MS80 SN: PP002



Response (%)





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MS-80 Pyranometer / 2017-01

 

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time (sec.)

3

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 

EKO Instruments Co., Ltd.

	
  

	
  

Measuring faster
Before the MS-80, EKO released the MS-56 pyrheliometer. These radiometers cansample much faster than previous versions. Faster sample rates allow the sensor to‘catch’ more accurately the peak irradiance values in case of rapid atmosphericchanges. Even on clear sky days the Solar irradiance seem to be constant on a minutescale. Due to atmospheric turbidity the irradiance can easily fluctuate by a few W/m2.
To detect sub-second changes, it is important to match the sampling rate of the dataacquisition System with the sensor response time. As rule of thumb, the sampling timeshould be below the response time (t = 63%) of the sensor. Hence data reduction canbe applied to store only minute values.
“Measuring faster”, requires faster sampling of the data. When comparing sub-second
sensors with traditional slower response sensors, the data acquisition system should bematched with the fastest sensor in the system. Under sampling conditions lead to
substantial mismatch and anomalies when sensors with different time constant arecompared with each other. Commonly when the data acquisition sampling time is set to
1s, it gives the impression that the fast sensor is instable. In contrary, it is the slower
sensor smoothing the irregular pattern of the actual irradiance.
Lowest offsets
Offsets are a consequence of thermal differences between the optics (domes or
diffusers) and detector, which are variable and influenced by conditional radiative andconvective factors (Irradiance / Net-IR / Temperature / etc). In order to optimize theoffset characteristics of a pyranometer, EKO changed the pyranometer architecture andgeometry to eliminate temperature effects between the optics and detector. Generally,a smaller diameter dome, gives a lower heat loss and cooling effect compared to larger
double dome concepts. In combination with the diffusor and isolated detector it cankeep the MS-80 sensor in a proper thermal balance under varying atmospheric andenvironmental conditions. Zero offset A, known as the “dome cooling” effect is absent
from the MS-80 and stays within the measurement uncertainty of 1 W/m2 specified in
the Net-IR range up to -200 W/m2 (unventilated / ventilated).

MS-80 Zero oﬀset A

Night time Sep. 28, Oct. 25, Oct. 27 2015 / Unventilated

2.0
1.5

MS80 SN: PP002

MS-80 SN: PP001

MS-80 SN: PP003

Irradiance (W/m2)

1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
-200

-180

-160

-140

-120

-100

-80

-60

-40

-20

0

Net-IR radiation by MF-11 (W/m2)

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Zero offset B is defined as the detector response caused by a gradual change of
ambient temperature or exposure to irradiance. The MS-80 typical zero offset B is
<1W/m2 / 5K per hour.

Long-term stability
A third-party test lab performed an extensive UV stability test (JIS B7751 "Lightexposure and light-and-water-exposure apparatus) and thermal cycle test to simulate
and validate the sensor performance over a long period of field operation. Results do
not reveal any degradation of the detector responsivity over time larger than 0.5%
taken into account the uncertainty of the measurement method.
Compared to all other pyranometers in the market the MS-80 has improved long-term
stability properties. Therefore, the recommended period of recalibration can beextended to 5 years, which is typically 2 years for other sensor models in the market.
The long-term stability of the sensor responsivity is less than 0.5% in a period of 5
years which makes it unique.
Based on the hermetically sealed construction and high quality sensor components
also the standard warranty period is 5 years. MS-80 has no drying cartridge eliminating
the need to replace the silicagel inside. All features that in combination make up themost cost effective pyranometer to date.
MS-80 accelerated UV exposure test
Annual amount UV radiation (300 - 400nm) in Tokyo

Sensitivity change (%)

1.0%
PPS004

PPS005

PPS006

0.5%

0.0%

-0.5%

-1.0%
0

5

10

15

20

25

Year

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EKO Instruments Co., Ltd.

	
  

	
  

Non-linearity
The detector responsivity is proportional to irradiance with a measurement uncertaintyof <0.2% in the range 100…1000 W/m2. To quantify the results, EKO developed an
accurate test method to verify the results indoors and outdoors.

MS-80 Non-linearity

Percentage deviation from the responsivity at 500 W/m2
due to the change in irradiance within 100Wm2 to 1000Wm2.
1.0%
MS-80 SN: PP001

MS-80 SN: PP003

MS80 SN: PP002

Responsivity (%)

0.5%

0.0%

-0.5%

-1.0%






















Irradiance level (%)

Cosine response

The single glass dome with diffusor is one of MS-80 unique aspects compared to other
Secondary standards pyranometers in the market. It has a true cosine/azimuth
response, which is plotted as deviation to the theoretical cosine response (W/m2).
MS-80 Directional response


 

MS-80 SN: PP003

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
 
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

 
























Zenith angle (deg.)

The cosine characteristics of each sensor will be tested for Solar zenith angles up
to 80º in 4 different azimuth directions. A test report of each MS-80 is provided
standard with every purchase.

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EKO Instruments Co., Ltd.

	
  

	
  

Spectral Selectivity
MS-80 has a thermopile detector and Quartz diffusor and is responsive to radiation
within the full Solar spectral range. The spectral selectivity complies with ISO 9060 anddefined as the percentage deviation of the product of spectral absorption and spectral
transmittance from the corresponding mean within 350 nm and 1500nm. In the figure
below the relative spectral response of MS-80 is plotted.

MS-80 Spectral Selectivity
Relative spectral response [-]

1.2
1.1
1.0

Spectral response [-]

0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
300

400

500

600

700

800

900
1000
1100
Wavelength*(nm)

1200

1300

1400

1500

1600

MS-80 Spectral selectivity

From the spectral response function the spectral error can be calculated within the
Solar spectral range (295nm – 4000nm). The solar spectrum is not a constant, but willchange with the path through the atmosphere as well as changing concentrations ofatmospheric constituents. Hence the integrated spectral error was calculated as afunction of airmass (AM1 to AM38) using the SMARTS model (developed by Dr.
Christian Guymard). The relative spectral errors and absolute errors are plotted as afunction of the corresponding solar elevation angle corresponding to a calibration at
the measurement condition AM1.5.

SMARTS spectra (AM1 – AM38)

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EKO Instruments Co., Ltd.

	
  

	
  

MS-80 Spectral error

Low temperature coefficient
Due to the embedded analog temperature compensation electronics, the detector has
a very low temperature coefficient. The MS-80 gives a linear output as a function ofirradiance in a wide temperature range, without the need for data correction.

MS-80 temperature response

Temperature Response (%)Responsivity change (%) as function of temperature

4.0%
3.5%
3.0%
2.5%
2.0%
1.5%
1.0%
0.5%
0.0%
-0.5%
-1.0%
-1.5%
-2.0%
-2.5%
-3.0%
-3.5%
-4.0%

MS80 SN: PP002

MS-80 SN: PP001

-30

-20

-10

0

10

20

MS-80 SN: PP003

30

40

50

60

Ambient Temp (deg-C)

Temperature characteristics of each sensor are tested in the range -20ºC to 50ºC. A
test report of each MS-80 is provided standard with every purchase.

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EKO Instruments Co., Ltd.

	
  

	
  

Tilt response
Percentage deviation from the responsivity at 0° tilt (horizontal) due to change in tilt
from 0°to 90°at 1000W/m2 irradiance

MS-80 Tilt Response
0.4%MS-80 SN: PP001

0.3%

MS-80 SN: PP003

MS80 SN: PP002

Tilt Response (%)

0.2%
0.1%
0.0%
-0.1%
-0.2%
-0.3%
-0.4%
0

15

30

45

60

75

90

Tilt (deg.)

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EKO Instruments Co., Ltd.

	
  

	
  

Outdoor performance
Observations of multiple MS-80 units with collocated secondary standard common
brand pyranometers were made. In the setup global horizontal irradiance is measured.
The illustrative figures show the measurement results obtained for various days andnight. Note the excellent agreement overall, MS-80 performance shows to be very
consistent during variable atmospheric conditions at day- and nighttime.
Nighttime offset
During nighttime, pyranometers tend to generate a negative output known as the zero
offset A effect. Which is one of the error sources typically detected for conventional
thermopile pyranometers. The nighttime offset is a clear performance indicator withrespect to the detector thermal balance and sensor susceptibility to offsets. During
overcast sky conditions, pyranometers offsets will be zero. However, for clear sky
conditions the offset is proportional to the Net radiation-IR (W/m2). The MS-80 shows
very low offset values under all nighttime conditions.

Nighttime oﬀset (ZOA)

ISO 9060 Secondary standard pyranometer
AMI-PV-Site Nov.21, 2015


MS80 SN: PP002

MS-80 SN: PP003

Common brands

Irradiance (W/m2)













 

12:00 12:20 12:40 1:00
AM AM AM AM

MS-80 Pyranometer / 2017-01

1:20
AM

1:40
AM

2:00
AM

2:20
AM

10

2:40
AM

3:00
AM

3:20
AM

3:40
AM

4:00
AM

4:20
AM

4:40
AM

EKO Instruments Co., Ltd.

	
  

	
  

Daytime offset
Pyranometer zero offsets usually get mixed with the irradiance signal and become
indiscernible during daytime. During clear sky conditions, it usually leads tounderestimation of the irradiance measurement. With the so-called “capping method”
the hidden zero offset A can be revealed. In the plot below the MS-80 results showthat zero offset are absent during day-time. Generally, zero offsets get larger due to thefact that the ambient temperature will increase and the sun will heat the sensor. A
greater temperature difference will cause the IR net-radiation values to increase.

Day-time oﬀset (ZOA)

ISO 9060 Secondary standard pyranometer
Capping method Dec.1st, 2015
CAP

OPEN

OPEN

Irradiance (W/

10$$
8$$

MS-80 SN: PP001

6$$

Common brands

4$$
2$$
0$$
!2$$
!4$$
!6$$
!8$$
!10$$

2:20 PM

2:40 PM

3:00 PM

3:20 PMThe low offset characteristics make the MS-80 pyranometer also highly suitable for
diffuse radiation measurements. With clear or overcast skies the diffuse irradiance isjust a fraction of the global irradiance. Hence the pyranometer offsets largely contributeto the measurement uncertainty. To measure diffuse irradiance in addition a Sun
tracker with shading system is required.

Irradiance measurements

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EKO Instruments Co., Ltd.

	
  

	
  

Irradiance data was measured every 10s and compared for various sky conditions,
respectively clear sky and partly cloudy. The MS-80 pyranometer show excellent
correlation for both conditions against a high-end pyranometer. During partial cloudy
conditions a fast detector response time matters. The correlation coefficient between
the two MS-80’s is better.
CMP22 VS MS-80 at AMI-PV-Site

CMP22 VS MS-80

Partial Cloudy 2015/11/30, 12/6, 12/10, 12/11, 12/21 - 2015

Clear sky 11/28,12/01,12/5,12/18 - 2015
CMP22%VS%PP101%

CMP22%VS%PP103%

Approx.%CMP22%VS%PP101%

Approx.%CMP22%VS%PP103%

CMP22%VS%PP103%

700

CMP22 VS PP101
y = 0.9926x + 3.5748

600

R² = 0.999
MS-80 Irradiance (W/m2)

500

MS-80 Irradiance (W/m2)

CMP22%VS%PP101%

Approx.%CMP22%VS%PP103%

400

CMP22 VS PP103
y = 0.9943x + 2.9462
300

R² = 0.999

700

CMP22 VS PP103
y = 0.9828x + 6.1069

600

R² = 0.992

500

400

CMP22%VS%PP101%
y%=%0.9771x%+%10.297%%
R²%=%0.99%

300

200
200

100

100

0
0

100

200

300

400

500

600

0

700

0

100

200

CMP22 Irradiance (W/m2)

300

400

500

600

700

800

CMP22 Irradiance (W/m2)

MS-80 PP101 VS PP103

MS-80 PP101 VS PP103 at AMI-PV-Site

Clear sky 11/28,12/01,12/5,12/18 - 2015

Partial Cloudy 2015/11/30, 12/6, 12/10, 12/11, 12/21 - 2015
800"

700

700"

600

y = 1.0054x - 4.1135
R² = 0.99969

y = 1.0016x - 0.5963
R² = 0.99994

MS#80&PP103&Irradiance&(W/m2)&

Approx.%CMP22%VS%PP101%

800

600"

MS-80 PP103 Irradiance (W/m2)

500

400

300

200

500"

400"

300"

200"

100

100"

0"

0
0

100

200

300

400

500

600

0

700

100

200

MS#80&PP101&Irradiance&(W/m2)&

300

400

500

600

700

800

8"

9"

10"

MS-80 PP101 Irradiance (W/m2)

MS-80 VS CMP22

Clear sky 11/28,12/01,12/5,12/18 - 2015
PP101 STDEV = 2.63 / PP103 STDEV = 1.96 
PP101"

PP103"

3500"

Count (number)

3000"

2500"

2000"

1500"

1000"

500"

0"
'10"

'9"

'8"

'7"

'6"

'5"

'4"

'3"

'2"

'1"

0"

1"

2"

3"

4"

5"

6"

7"

Diﬀerence"(W/m^2)"

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Expanded measurement uncertainty
A brief look at the MS-80 specification list gives an impression of the many parametersthat affect the radiation measurements. Fortunately, all these individual error sources,
which have a small magnitude, will rarely affect the measurement at the same time.
However, it is very difficult to calculate the combined measurement uncertainty
because it is nearly impossible to isolate the individual measurement conditions todetermine the corresponding errors. This illustrates the difficulty and complexity of themeasurement uncertainty calculation. However, using the pyranometer specifications,an assessment can be made for the measurement uncertainty of ISO 9060 Secondary
Standard pyranometers. For the analysis, several assumptions were made with respect
to the individual specifications considering the measurement and calibration
uncertainty and conditions. The specifications for the ISO9060 pyranometer classes are
based on the specifications for a common brand model in the market. Generally, thesensor specifications are slightly better than the limiting specification defined by ISO
9060.
Table 1: Expanded uncertainty secondary standard pyranometers
MS-80

High-end

Calibration accuracy* (%)

0.7

1.2

Commonbrand
1.2

Zero offset A (W/m2)

1.0

3.0

7.0

7.0

Zero offset B (W/m2)

1.0

1.0

2.0

2.0

Non-Stability (%)

0.5

0.5

0.5

0.8

Non-linearity (%)

0.2

0.2

0.2

0.5

Directional response (W/m2)

10.0

5.0

10.0

10.0

Spectral selectivity** (%)
Temperature response*** (%)

0.4
0.5

0.4
0.5

0.4
1.0

0.7
1.0

Tilt response (%)

0.2

0.2

0.2

0.5

Expanded uncertainty (k=1.96)

1.6%

1.6%

2.3%

2.5%

ISO 9060
1.2*Calibration uncertainty commonly specified in the market (EKO Calibration uncertainty= 0.7% K=1.96) / **Effect of sensor spectral selectivity / ***Calibration reference
temperature 20ºC (-20ºC to 50ºC) / (Response time not accounted for)
The expanded measurement uncertainty associated with the ISO 9060 pyranometerclass is calculated as the square root of the sum of the squares of the individual
uncertainties and could be considered the worst case scenario.

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Calibration
The MS-80 pyranometer is calibrated indoors against a calibrated MS-80 reference
pyranometer using a solar simulator (1000 W/m² AM1.5 class AAA) as source (Method
ISO 9847). The pyranometer is situated on a horizontal table and aligned to the opticalaxis of a normal incidence light source thus eliminating some of the sources of error
mentioned above. By alternating the position of the calibrated reference pyranometerwith the test pyranometer the output signal of both pyranometers are recorded andused to solve the equation of the unknown sensitivity variable. The operating
conditions are maintained constant (e.g. ambient temperature and normal incidence
irradiance), hence the pyranometer uncertainty figure is determined throughsummation in quadrature of the sensitivity uncertainty of the reference (Ur), uncertainty
of temperature (Ut), repeatability (Ur) and normal distribution (d).
1) Uncertainty of reference (Ur)0,31%2) Uncertainty of temperature (Ut)
3) Repeatability (Ur)

0,14%
0,04%

4) Distribution (d)0,03%Total uncertainty (Uc)

0,34%

Expanded uncertainty (U)0,69%The expanded calibration uncertainty
associated with the pyranometer sensitivity
figure is calculated as the square root of
the sum of the squares of the reported
uncertainties: 1.96 x √((Ur^2 + Ut^2 +Ur^2+ d^2))

The MS-80 Secondary Standard pyranometer reference sensor is calibrated against
the primary standard PMO-6 per the sun-and-shade method under ISO 9846. The
primary standard is directly traceable to the World Radiometric Reference (WRR) andmaintained in the group of standard radiometers calibrated every 5 years during theInternational Pyrheliometer Comparison (IPC). EKO also performs an annual calibration
check of the reference instrument during the National Renewable Energy Laboratory(NREL) Pyrheliometric Comparison (NPC).
EKO Instruments Co. Ltd. calibration laboratory is accredited and certified by PJLA (Ref:#74158) to perform pyranometer and pyrheliometer calibrations in accordance withthe requirements of ISO/IEC17025, which are relevant to calibration and testing.
EKO offer a unique manufacturer calibration service for pyranometers andpyrheliometers in-house. Based on the applied calibration methods EKO provides thebest quality Solar sensor calibrations compliant to the international standards definedby ISO/IEC17025 / 9847 (Indoor method) and 9059 (Outdoor method), as defined by
the scope of calibrations.
ISO/IEC17025 provides a globally accepted basis for laboratory accreditation thatspecifies the management and technical requirements.
With calibrations performed at the EKO Instruments laboratory we enable ourcustomers to:• Clearly identify the applied calibration methods and precision• Be traceable to the World Radiation Reference (WRR) through defined industrial
standards:- ISO9846 Calibration of a pyranometer using a pyrheliometer- ISO9847 Calibration of field pyranometer by comparison to a reference
pyranometer- ISO9059 Calibration of field pyrheliometers by comparison to a reference
pyrheliometer- Obtain repeatable and reliable calibration test results through consistent
operations yearly examined independently to assure strict compliance to therequirements.
Our clients will obtain the highest level of confidence when purchasing an
ISO/IEC17025 calibrated sensor. EKO’s Accredited lab is regularly re-examined toensure that they maintain their standards of technical as well as managerial expertise.

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MS-80 market value
The MS-80 pyranometers combines all value-added functions such as the MV-01
ventilator, heater, and different industrial interfaces (4-20mA or MODBUS®).
The MS-80A is a MS-80 with built in 4-20mA converter, which is compatible to theindustrial output standards. Due to the ultra-low temperature dependency andexceptional non-linearity characteristics, the converter guarantees an optimal sensor
performance, under any environmental conditions. For easy conversion, the output is
set to 4-20mA | 0 - 1600 W/m2. With the optional USB controller and EKO Sense
software, the converter settings can be freely changed. This tool will be needed in casethe sensor sensitivity might need to be changed after a periodical Solar sensor recalibration.
The MS-80M is a MS-80 with built in MODBUS® RTU 485 converter, which iscompatible to the industrial output standards. As with the MS-80A, the ultra-low
temperature dependency and non-linearity characteristics of the MS-80 guarantee an
optimal synergy of performance between the sensor and converter resulting inuncompromised data quality under any environmental conditions. The MS-80M with
MODBUS® converter can accommodate a local network of up to 100 different
pyranometers and converter units. Each converter can be addressed and connected inparallel. The mV signal of the Solar sensor will be converted to irradiance between 0 1600 W/m2. In this case, the sensitivity factor of the Solar sensor will be set to theconverter. With the optional USB controller and EKO Sense software the converter
settings can be freely changed. This tool will be needed in case the sensor sensitivity
might need to be changed after a periodical Solar sensor re-calibration.
The MS-80 pyranometers are manufactured in a consistent way followed by strict
quality inspection and performance evaluation. For each sensor, the directional
response and temperature dependency are measured and validated through ameasurement report that comes with the sensor. EKO provides a unique calibration
compliant to the international standards defined by ISO/IEC17025 / 9847.
Versatile design coupled together with unique performance and stability characteristics
make the MS-80 the most distinct pyranometer on the market. MS-80 detector
architecture and new optical design can be clearly identified. Major performance gains
have occurred in response time, long-term stability, and reduction of offsets. A newgeneration of pyranometers and a new chapter in pyranometer development are being
written by EKO Instruments.
The combination of MS-80 with the compact MV-01
ventilator and heater makes that the forced air can beheated effectively and will keep the sensor dome andcover free of dew, fog, ice, and snow especially during
severe winter conditions. The MS-80 offset characteristics
will not change in combination with the MV-01 ventilator
and heater. The 7W heater can heat up the air to 1-2ºC
above ambient temperature, which due to the offset
immunity can only be done safely with the MS-80. The
heater and ventilator are suggested, particularly over areas
impacted by dew, frost, snow, and dust.

For any questions, please contact us at one of the EKO offices:Japan :
Europe:USA :info@eko.co.jp / www.eko.co.jp
info@eko-eu.com / www.eko-eu.com
info@eko-usa.com / http://www.eko-usa.com

MS-80 Pyranometer / 2017-01

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EKO Instruments Co., Ltd.