37 Years of Product Development for Line Mounted, Self-Powered Transmission Line Sensor Transmitter Receiver Unit (TSTR) 
July 1976 - Series 100 July 1977 - Series 200          (2 parameters) 1978 - Series 300                  (4 parameters) 1978 - Series 400                  (4 parameters) Oct 1982 - Series 500           (5 parameters) Oct 1992 - Series 500           (5 parameters) 2011’ - Series 500 Basic                   (10 Parameter) 2011’ - Series 500 Option A              (16 Parameter) 2011’ - Series 500 Option B               (27 Parameter)
First self powered line mounted device for measuring conductor temperature in the world (mounted on 230kV line) First self powered line mounted device (2) parameter in the world (mounted on 230kV line) First self powered line mounted device (4) parameter in the world (mounted on 230kV line) First self powered line mounted device (4) parameter transmitter of data using PLC in the world (mounted on 230 kV line) First self powered line mounted device  (5) parameter without line shutdown in the world (mounted on 115 kV line) First self powered line mounted device (5) parameter with ultrasonic sag/clearance measuring without line shutdown in the world (mounted on 345 kV line) First self powered, line mounted device  (10) parameter without line shutdown in the world – including weather station, line current, fault current, lightning current, undisturbed conductor temperature, GPS and transfer trip First self powered, line mounted device  (16) parameter without line shutdown in the world – including weather station, line current, fault current, lightning current, undisturbed conductor temperature, line sag, GPS and transfer trip First self powered, line mounted device  (27) parameter without line shutdown in the world – including weather station, line current, fault current, lightning current, undisturbed conductor temperature, line sag, GPS, transfer trip, incorporating voltage sensing, all power quantities, conductor vibration and synchro-phasor
Induction loop power supply Induction loop power supply Split magnetic core power supply - spherical housing Split magnetic core power supply - spherical housing Split magnetic core power supply – “C” cores Split magnetic core power supply – “C” cores
Low power transmitter - 300 feet Low power transmitter - 300 feet
 Line shutdown required  Line shutdown required (1) Ambient temperature (1) Ambient temperature Powered from line current – threshold current 200A Powered from line current – threshold current 100A Split magnetic core power supply - “C” cores Split magnetic core power supply - “C” cores Split magnetic core power supply - “C” cores
(1) Wrapped tc sensor between outer stranding (1) Ambient Tempurture (2) Total hemispherical solar radiation (2) Total hemispherical solar radiation
(2) Wrapped tC sensor between outer stranding  (3) Line current - transformer secondary shorted (3) Line current - transformer secondary shorted (1) Spring loaded conductor temperature sensor (1) Spring loaded conductor temperature sensor Powered from line current – threshold current as low as 25A with LTPS. Powered from line current – threshold current as low as 25A with LTPS. Powered from line current – threshold current as low as 25A with LTPS.
(4) "Plowed-in" conductor temperature sensor under 1st layer of stranding (4) "Plowed-in" conductor temperature sensor under 1st layer of stranding
Ground Base Weather Station Ground Base Weather Station High power transmitter - 1 watt, concealed flush mount antenna Power Line Carrier (PLC) current injection-data transmitted on line (2) Ambient temperature (2) Ambient temperature “Snap-in” jaws – 0.5 inch to 2.0 inch conductor sizes “Snap-in” jaws – 0.5 inch to 2.0 inch conductor sizes “Snap-in” jaws – 0.5 inch to 2.0 inch conductor sizes
(2) Rainfall                                                                                                                                                   (3) Rainfall                                                                                                                                                   (3) Total solar radiation (3) Total solar radiation
(3) Direct Radiation - pyroheliometer (4) Direct Radiation - pyroheliometer Line shutdown required Line shutdown required (4) Line current-shorted transformer secondary (4) Line current-shorted transformer secondary   (1) Undisturbed conductor temperature sensor – adjustable for all conductor sizes  (1) Undisturbed conductor temperature sensor – adjustable for all conductor sizes       (1) Undisturbed conductor temperature sensor – adjustable for all conductor sizes
(4) Total Radiation - pyranometer (5) Total Radiation - pyranometer
(5) Ambient temperature (6) Ambient temperature Ground Base Weather Station Ground Base Weather Station (5) Line sag-inclinometer (5) Line sag-ultrasonic      (2) Ambient Temperature        (2) Ambient Temperature        (2) Ambient Temperature
(6) Wind Velocity (7) Wind Velocity (5) Rainfall                                                                                                                                                   (5) Rainfall                                                                                                                                                   Adjustable  mounting jaws-spring loaded lower core Adjustable  mounting jaws-spring loaded lower core      (3) Total Solar Radiation        (3) Total Solar Radiation        (3) Total Solar Radiation
(7) Wind Direction (8) Wind Direction (6) Direct Radiation - pyroheliometer (6) Direct Radiation - pyroheliometer      (4) Humidity        (4) Humidity        (4) Humidity
(7) Total Radiation - pyranometer (7) Total Radiation - pyranometer Radio transmitter 450 MHz-1 watt Radio transmitter 450 MHz or 900MHz-1 watt      (5) Barometric Pressure        (5) Barometric Pressure        (5) Barometric Pressure
Line Parameters Line Parameters (8) Ambient temperature (8) Ambient temperature       (6) Effective Wind Velocity        (6) Effective Wind Velocity        (6) Effective Wind Velocity
(8) Line sag from load cells mounted at deadend of line (9) Line sag from load cells mounted at deadend of line (9) Wind Velocity (9) Wind Velocity
      (7) Line Current – “C” Loop        (7) Line Current – “C” Loop        (7) Line Current – “C” Loop
(9) Line Current - C.T.'s at station (10) Line Current - C.T.'s at station (10) Wind Direction (10) Wind Direction       (8) Fault Current & Waveforms        (8) Fault Current & Waveforms        (8) Fault Current & Waveforms
          (9) Fault Current Direction        (9) Fault Current Direction        (9) Fault Current Direction
Line Parameters Line Parameters      (10) Lightning Stroke Current & Waveforms      (10) Lightning Stroke Current & Waveforms        (10) Lightning Stroke Current &  Waveforms
(11) Line sag from load cells mounted at deadend of line (11) Line sag from load cells mounted at deadend of line Radio Transmitter/Receiver 450 MHz to 1.2 GHz Radio Transmitter/Receiver 450 MHz to 1.2 GHz Radio Transmitter/Receiver 450 MHz to 1.2 GHz
(12) Line Current - C.T.'s at station (12) Line Current - C.T.'s at station Variable Frequency Antenna Variable Frequency Antenna Variable Frequency Antenna
GPS Location GPS Location GPS Location
Transfer Trip Transfer Trip Transfer Trip
 (11) Line Sag & Clearance  (11) Line Sag & Clearance
 (12) Rain Sensor  (12) Rain Sensor
 (13) Ice Thickness  (13) Ice Thickness
 (14) Tower Tilt – Broken Conductor  (14) Tower Tilt – Broken Conductor
 (15) Insulator Swing  (15) Insulator Swing
 (16) Real Time Thermal Ratings
(17) Line Voltage
       (18) Fault Voltage & Wave Forms
       (19) Lightning Stroke Voltage & Waveforms
       (20) Total Harmonic Current Distortion THDi
       (21) Total Harmonic Voltage Distortion THDv
       (22) Power Factor
       (23) MW
       (24) MVAr
       (25) MVA
       (26) Conductor Vibration
       (27) Synchro-phasor