Questions Answered

The sun sensor is a crucial component of our STR sun trackers, helping to ensure accurate tracking.

STR sun trackers follow the sun by calculating its position. The position of origin is determined by the orientation and levelling of the tracker. However, it can be difficult to find the perfect position of origin in practice. Consequently, misalignment of the tracker and all the solar sensors attached can occur despite the precise solar position calculation.

With STR sun trackers, the sun sensor is part of an active feedback system, compensating for any deviation from the ideal position of origin.

All STR sun-trackers are equipped with a standard sun sensor to guarantee high precision sun tracking without manual adjustment.

Check out our How To ‘Set-up your MS-57 Pyrheliometer‘ video on YouTube or visit the STR sun tracker product pages to find out more.

Failure to properly affix a heat flux sensor with the material you wish to measure can lead to local hot spots; or cold spots in cases of negative heat flux.

Hot spots will alter your thermal gradients and change the convective and conductive heat transfer coefficients. Simply putting a sensor against a surface may still result in a heat flux reading, but the contact resistance will keep the reading from being particularly meaningful.

To improve the thermal contact of flat layered sensors, use a thermally conductive adhesive to help minimize contact resistance.

Software, manuals, specification sheets and more are all accessible via product pages and our dedicated ‘Downloads’ page.

Search by product type and specific product. Older and obsolete products are also included.

The MC-11 is a 4-20mA digital signal converter designed to convert the voltage output of a solar radiation sensor into a 4-20mA current output.

To convert the mA output into voltage, you will need to connect a voltmeter.

First, apply a shunt resistance to the 4-20mA current loop circuit and measure the voltage at both ends of the resistor. When a 250Ω shunt resistor is applied, the 4-20mA is converted into 1-5V.

Prepare the shunt resistor according to the measurement range of the voltmeter you are using.

When selecting power supply voltage, keep in mind that the voltage decreases when using a shunt resistor; that minimum supply voltage and the voltage drop across the shunt resistor.

EKO offers a range of converters to change sensor outputs. 

The MC-11 digital signal conditioner converts the voltage output of a solar radiation sensor into a 4-20mA current output. The converter can be used with all passive EKO radiometers or any other mV sensor and can be connected to dataloggers or inverters with a 4-20mA input channel.

The sensor cable can be extended over long distances using the signal conditioner without any signal loss or potential electromagnetic interference in noisy industrial environments.

The MC-20 MODBUS 485 RTU converter is a digital signal conditioner that converts the voltage output of a solar radiation sensor, PT-100 or 10kΩ NTC temperature sensor into a MODBUS 485 RTU output.

The converter can be used with all passive EKO radiometers or other mV sensors connected to data loggers or inverters with a MODBUS 485 RTU input channel.

By using the signal conditioner, the sensor cable can be extended over long distances without any signal loss or potential electromagnetic interference in noisy industrial environments.

With MODBUS up to 100 different sensors and converter units can be addressed and connected in parallel.

All EKO products are built to the highest quality standards and are thoroughly tested and calibrated during production.

Even so, regular inspection of your sensor and data is advised to ensure consistent performance. Instant changes to the regular data pattern or collocated measurements, for example, may indicate a performance change or issue that necessitates servicing or recalibration.

Data redundancy, that is, multiple instruments used together to analyse and compare irradiance data, can also help you catch any issues.

The internal diagnostics systems of our S-Series range of sensors are another big help, giving users visibility over internal temperature, humidity, tilt and roll angle, helping to ensure optimum performance without the need for regular physical checks.

If you have any doubts or questions about the performance of your sensor, please contact your local EKO office using our online contact form.

Our STR-21G and STR-22G sun trackers do not require recalibration or re-adjustment. They are built to automatically track the sun’s position through calculation and active measurement of the sunspot.

Time information used for the solar position algorithm is retrieved by the GPS receiver and is frequently updated. The sun sensor actively measures the actual position of the sunspot and compensates for misalignments.

Find out more and explore available downloads for the STR-21G by visiting the product page.

We recommend a monthly check to ensure that the sun tracker cables and cables for all associated solar sensors are still in place, that the sun tracker is still at a horizontal level and that the sun sensor front window is not dirty.

Other than that, no specific maintenance is required.

EKO Instruments Co., Ltd. (EKO) calibration laboratory is accredited and certified by PJLA (Ref: #74158) to perform pyranometer and pyrheliometer calibrations per the requirements of ISO/IEC 17025:2017, which are relevant to calibration and testing.

EKO was the first manufacturer in the world to offer an in-house calibration service for pyranometers and pyrheliometers, and we provide a calibration certificate with all new and recalibrated pyranometers and pyrheliometers.

Customers can have the highest level of confidence when purchasing an ISO/IEC 17025:2017 calibrated sensor, or when sending an existing sensor to us for recalibration. EKO’s accredited laboratory status is regularly re-examined to ensure that we maintain the required standards of technical expertise.

EKO Instruments offers Pyranometer, Pyrheliometer & Viscometer recalibration from our accredited global calibration laboratory in Tokyo, Japan.

EKO offers pyranometer recalibration at our laboratories in Japan and the Netherlands. We also work with a network of partner organisations, including specialised laboratories, meteorological institutes, and universities, to offer recalibration services worldwide.

You can book a recalibration via our services page. For more details or questions about available recalibration services in your region, please contact your local EKO office via the contact page.