1. The Eppley Laboratory, Inc. 12 Sheffield Avenue, Newport, RI 02840
Since the dawn of time,
man has studied the sun…
… and EPPLEY has been providing
traceable measurements to the
The Pyrheliometric Scale for 85 years.
Presented by Tom Kirk, President
IPC-XII Symposium 2015

2. Captain Marion Eppley founded The Eppley Laboratory in 1917 to supply Standard Cells (Voltage Sources).
IPC-XII Symposium 2015

3. Later known as the 180º Pyrheliometer or “Light Bulb Pyranometer”.
In 1930, Eppley began commercially manufacturing 10- and 50-junction models of pyhreliometers (pyranometers) based on the design of Kimball and Hobbs.
Later known as the 180º Pyrheliometer or “Light Bulb Pyranometer”.
IPC-XII Symposium 2015

4. From 1930 until 1957, all calibrations were traceable to The Smithsonian Pyrheliometric Scale (1913, 1932). Eppley maintained a reference group of six (6) 180º Light Bulb Pyranometers calibrated by the US Weather Bureau and by the National Bureau of Standards (NBS).
IPC-XII Symposium 2015

5. Table Mountain (May 1957)
In 1937, an Abbot Silver Disk Pyrheliometer (SI73) was added to the reference group for calibrating Eppley Normal Incidence Pyrheliometers and for periodic intercomparisons.
IPC-XII Symposium 2015

6. In 1957, the International Pyrheliometric Scale of 1956 (IPS 1956) was adopted. This new scale was maintained at Eppley through three (3) Stockholm Ångström pyrheliometers later augmented by three (3) Eppley manufactured Ångström pyrheliometers. Various Comparisons were held in Stockholm, Davos, Smithsonian, Table Mountain, Armenia and Newport.
IPC-XII Symposium 2015

7. IPC-IV (1975) included six Absolute Cavity designs including Eppley’s PACRAD Radiometer (EPAC) based on JPL’s Kendall PACRAD III. These results led to the World Radiation Reference (WRR) being established in 1979 by the World Radiation Center (WRC) as a replacement to the IPS In the 1990’s, Eppley donated EPAC to PMOD-WRC.
IPC-XII Symposium 2015

8. Table Credit: Karl Boer, Advances in Solar Energy (2012)
New River Comparisons
Seven (7) Comparisons of different models of Cavity Radiometers were held between 1978 and 1985 at DSET’s New River, AZ facility.
IPC-XII Symposium 2015

9. Eppley’s HF (Hickey-Frieden) Absolute Cavity Radiometers participated in IPC V (1980). HF was donated to PMOD-WRC and is included in the World Standard Group (WSG).
IPC-XII Symposium 2015

10. Also participate in NREL’s NPC’s.
AHF has participated in every IPC since AHF has participated in every IPC since 1990.
Also participate in NREL’s NPC’s.
IPC-XII Symposium 2015

11. WHAT’S NEW?
SPP Pyranometer sNIP Pyrheliometer GPP Pyranometer SMT Tracker Controller VB AWX v1.27 for AHF (Special Thank: NOAA-GMD)
IPC-XII Symposium 2015

12. Factory Calibrations of NIP and sNIP Pyrheliometers are done outdoors in accordance with procedures described in ISO These can be done against our transfer standard NIPs and sNIP, or if the customer requests, can be done against Cavity Radiometers.
IPC-XII Symposium 2015

13. Factory Calibrations of PSP, SPP and GPP Pyranometers are performed according to procedures described in ISO 9847 Section in Eppley’s Integrating Hemisphere.
IPC-XII Symposium 2015

14. Calibrations of Transfer Standards PSP, SPP and GPP Pyranometers are done outdoors against Cavity Radiometer and shaded 8-48 Black & White Pyranometers according to procedures described in ISO 9846.
IPC-XII Symposium 2015

15. The Eppley Laboratory, Inc. 12 Sheffield Avenue, Newport, RI 02840
Thank you!
Please visit
for more information on the new sNIP Pyrheliometer and the new SPP & GPP Pyranometers.
IPC-XII Symposium 2015