Overview

EKO Instruments presents the improved STR-Sun Trackers STR-21G and STR-22G with fully automated set up procedure through a GPS receiver providing increased reliability and enhanced functionality.

Features

The new STR Sun Trackers now offer standard built-in GPS function with new features

Accurate set up by automatic retrieval of position and time at any place on earth
Easy installation and operating without need of a computer
Operating status indication by LED signal
Continuous clock synchronization enabling permanent reliable and accurate positioning of the solar radiometers measuring direct, diffuse and global irradiance

Standard STR-21G / 22G Sun Tracker system includes

Single arm STR-21G or Double arm STR-22G Tracker with built in GPS
Four Quadrant Sun Sensor which automatically compensates for mechanical misalignment
Pyrheliometer Mount (suitable for any pyrheliometer model)
Levelling Tripod with spirit level
Diagnostics and control software

Sun Tracker Options

Various top mounting plates for all common pyranometers or pyrgeometers models
Additional pyrheliometer mounts
Shading ball assembly (1 or 2 radiometer positions)
DC operating version (18 - 30 VDC / 15W power consumption)

Outline drawing (STR-21G)

Mounting Possibility

Specifications

Model	STR-21G Single Arm	STR-22G Double Arms
Motor	Stepping motor
Motor driving mode	Half step
Driving technology	Harmonic Drive
Pointing accuracy	< 0.01° (Solar Elevation: 0 to 87°)
Angle resolution	0.009°
Rotation angle	Elevation-angle(-15° to +95°) Azimuth-angle(0° to +/-180°)
Torque	12 Nm	24 (12+12) Nm
Payload	7kg balanced	15kg 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 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 -40 to +50°C
Altitude for solar position calculation	No Limitation
Communication	RS-232C, 9600bps, 8N1
Power requirement	AC100 to 240V, 50/60Hz, 20W DC18 to 30V, 15W for DC optional Sun Tracker
Dimension	430(W) x 380(D) x 440(H) mm
Weight	14.5 kg	15.5 kg
Registered Trademark by Harmonic Drive Systems,Inc. in Japan, China, Korea, Taiwan

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