EKO Instruments – STR-serien – Sol-tracker

Modell: STR-serien
Produsent: EKO Instruments

Varenummer: 4993 Kategorier: ,
Bjørn Cato Solli 3

Bjørn Cato Solli

Luft og miljø
22 09 40 54

The STR-series a compehensive range of compact single and double arm Solar trackers suitable to accomodate all kinds of solar radiometers. The heavy duty STR-32G is capable to handle 4 times the load of the STR-21G and 22G.

EKO Sun Trackers are very compact, robust, relatively light weight and very power efficient. Inside the Sun Tracker a Harmonic Drive with advanced motion control unit is used on each output shaft. Harmonic drive is a leading drive technology for those application where high precision, durability, low backlash, high transmission ratios and torque is required. Due to its compact design and high transmission ratio small motors could be used to keep the power consumption low.

EKO has a long tradition manufacturing fully automatic meteorological Sun Trackers which are used to accurately position solar sensors (Pyrheliometers, Pyranometers, Pyrgeometers) towards the sun, either to expose or shade a sensor from the direct sun beam. In combination with a pyrheliometer (DNI sensor), shading assembly and Pyranometer, respectively the direct and diffuse radiation component can be measured. Using the sum component calculation method the global radiation can be accurately determined when the 2 components are added (Cosine zenith angle x (Direct) Diffuse).

The maximum payload is tuned to use several solar sensors to measure direct, diffuse and global radiation. To measure diffuse radiation a shading ball assembly is required in combination with the double arm STR-22G. To put 2 sensors in the shade a double shading ball version is available.

Nowadays all the STR-Sun Trackers have a built in GPS receiver for easy installation and accurate sun tracking. During automatic set up the position coordinates and time information is used to calculate and control it to the exact sun position. The standard sun sensors compensates for any geometrical misalignment and due to this makes the measurement more precise.

Selger Bjørn Cato Solli
Model STR-21G STR-22G STR-32G
Single Arm Double Arm Double Arm
Motor Stepping motor
Driving technology Harmonic Drive
Pointing accuracy < 0.01° (Solar Elevation: 0 to 87°)
Angle resolution 0.009° 0.009°  0.0036°
Rotation angle Elevation-angle(-15° to 95°)
Azimuth-angle(0° to /-180°)
Torque 12 Nm 24 (12 12) Nm 60 (30 30) Nm
Payload 7kg balanced 20kg balanced  60kg balanced
Tracking mode Sun-sensor mode and Calculation mode are automatically switched.
Tracking accuracy of Sun-sensor mode /- 0.01°
Sun-sensor field of view /- 15°
GPS Receiver Integrated receiver
GPS Sensor measurement accuracy Horizontal Position: Below 15m (2drms). GPS Positioning
GPS Sensor positioning start time < 5min. (depends on the recieving condition.)
LED Indicator Power, GPS status
Environmental Protection IP65
Temperature range From -30 to 50°C
Altitude for solar position calculation No Limitation
Communication RS-232C, 9600bps, 8N1
Power requirement AC100 to 240V, 50/60Hz, 50W  AC100 to 240V, 50/60Hz, 50W
DC21 to 32V, 20W for DC optional Sun Tracker (*Power consumption 10W)
Dimension 430(W) x 380(D) x 440(H) mm 430(W) x 380(D) x 250(H) mm
Weight 14.5 kg 15.5 kg 15 kg
Sun sensor Integrated with Sun tracker
Pyrheliometer mount Standard Standard Optional
Levelling tripod Standard Standard Optional
Diagnostics and control software Standard
*Power consumption under normal load and operating conditions @ 25°C.