EKO Instruments · Solar radiation
Sun trackers and pyrheliometers from EKO Instruments
Distributor for EKO Instruments in SwedenA sun tracker keeps a pyrheliometer pointed at the sun all day and can shade a pyranometer at the same time. Direct, diffuse and global radiation are then measured separately. EKO Instruments’ sun trackers set themselves up using GPS and fine-tune their pointing with a sun sensor.
Sun trackers, pyrheliometers and systems
The sun tracker carries the pyrheliometer. With a shading disk or shading balls, a pyranometer on the same tracker measures the diffuse radiation.
Sun tracker, one arm
STR-21G
For one pyrheliometer, with an optional shading disk for diffuse radiation.
- Payload up to 7 kg.
- 24 V, below 20 W.
Sun tracker, two arms
STR-22G
For direct, diffuse and global radiation, with shading balls.
- Payload up to 15 kg.
- 24 V, below 20 W.
Heavy-duty sun tracker
STR-32G
For large set-ups, for example with spectroradiometers.
- Payload up to 60 kg.
- Room for two pyrheliometers.
Pyrheliometer, Class A
MS-57SH
A digital pyrheliometer with a heated window, for direct solar radiation.
- Modbus RTU and SDI-12.
- Response time below 0.2 s.
Pyrheliometer, analogue
MS-57
An analogue Class A pyrheliometer with window heating.
- Millivolt signal.
- Opening angle 5°.
Without a sun tracker
MS-80SH Plus+
The MS-80SH pyranometer with a rotating shadow band and control unit, giving global, diffuse and direct radiation.
- Diffuse radiation is measured with the shadow band, direct radiation is calculated.
- Modbus RTU, below 6 W.
- Made for −20 to +70 °C.
Compare the sun trackers
The main differences at a glance.
| STR-21G | STR-22G | STR-32G | |
|---|---|---|---|
| Arms | One | Two | Two |
| Payload | 7 kg | 15 kg | 60 kg |
| Torque | 12 Nm | 24 Nm | 60 Nm |
| Pointing accuracy | Better than 0.01° | Better than 0.01° | Better than 0.01° |
| Pyrheliometers | One | One | Two |
| Shading for diffuse radiation | Shading disk, optional | Shading balls, optional | Shading ball, optional |
| Power | 24 V, below 20 W | 24 V, below 20 W | 24 V, below 25 W |
| Lowest operating temperature | −40 °C | −40 °C | −40 °C |
| Protection | IP65 | IP65 | IP65 |
Swipe sideways to see the whole table. Simplified figures. Full specifications and manuals are available from EKO Instruments ↗.
Complete radiation stations
EKO sells the STR-21G sun tracker as a complete station under the name Solar Monitoring Station. The STR-21G-SH0 has the MS-57SH pyrheliometer and measures direct radiation. The STR-21G-SH2 adds a shading disk and the MS-80SH, and measures direct, diffuse and global radiation.
We build the station with a stand or mast, power supply and a Campbell Scientific data logger, level the sensors and make sure the data arrives.
- Direct radiationPyrheliometer on a sun tracker.
- Diffuse radiationShaded pyranometer.
- Global radiationUnshaded pyranometer.
Suited to
Reference stations
All three radiation components measured separately, with Class A sensors.
Research
Sun trackers that also carry spectroradiometers for the spectrum of direct radiation.
Solar power
Data for monitoring and for comparing calculated and actual production.
Simpler set-ups
The MS-80SH Plus+ gives all three components without a sun tracker.
What we do
Choice and quote
We help you choose class, output and set-up and send you a quote.
Wiring
The sensors are connected to a Campbell Scientific data logger or directly to your system.
Installation
Mounting, levelling and alignment on site, and a check that the data arrives.
Service and calibration
Cleaning and checks under a service agreement, and help when the sensors are due for recalibration.
Frequently asked questions about sun trackers
Do we need a sun tracker?
Only if direct radiation is to be measured with high accuracy. For global radiation a pyranometer is enough, and the MS-80SH Plus+ gives all three components without a sun tracker.
How is the sun tracker set up?
It takes time and position from GPS and fine-tunes its pointing with the sun sensor. During installation we level the tracker and align the sensors.
How much power does the sun tracker draw?
Below 20 W at 24 V for the STR-21G and STR-22G, and below 25 W for the STR-32G.
Does the sun tracker cope with winter?
The sun trackers are made for temperatures down to −40 °C and are sealed to IP65. The MS-80SH Plus+ is made for −20 to +70 °C.
More from EKO Instruments
Would you like a quote for a radiation station?
Tell us which radiation components you want to measure and where, and we will suggest sun tracker, sensors and set-up.