Radiometers (PAR, rad)
RBR offers PAR radiometers and narrow-band radiometers with a fixed channel width. Additionally, we support PAR sensors from LI-COR.
PAR sensors measure intensity of visible light at frequencies associated with photosynthesis. Narrow-band radiometers are available in a variety of wavebands.
RBR radiometers
The RBRsolo³ PAR and RBRsolo³ rad instruments look identical and share several specifications.
The RBRsolo³ PAR and RBRsolo³ PAR | deep use the cosine photosynthetically active radiation sensors which can measure light within one hemisphere.
The RBRsolo³ rad and RBRsolo³ rad | deep use radiometers measuring narrow-band light with a fixed channel width, available in a variety of wavebands. Both centre wavelength and channel width are factory-configured.
Optical radiometry
| Parameter | Value |
|---|---|
Dynamic range |
>5.5 decades (nominal) |
Initial accuracy1 |
±2% |
Linearity |
±1% |
Operating temperature range |
-5°C to 35°C |
Cosine response error (water) |
±5% at 0-60°, ±10% at 61-82° |
Azimuth error (water) |
±1.5% at 45° |
Out-of-band rejection2 |
>25dB (typical), OD 2.5 |
1 RBR calibrates radiometers with NIST traceable references.
2 Out-of-band rejection is wavelength-dependent for narrow-band radiometers.
PAR
| Parameter | Value |
|---|---|
Wavelength range |
400nm to 700nm |
Full scale range |
0 to 5000µmol/m²/s (minimum) |
Resolution |
±0.010µmol/m²/s |
Narrow-band channels
| Parameter | Value |
|---|---|
Centre wavelengths (CWL)1 |
380 / 413 / 445 / 475 / 488 / 508 / 532 / 560nm |
Full width at half-maximum (FWHM) |
10nm (25nm for CWL 475nm) |
Full scale range |
0 to 400µW/cm²/nm (minimum) |
Resolution2 |
±0.001µW/cm²/nm |
1 Other CWL options within the 300-1100nm range are available upon request. Contact RBR for more information.
2 Resolution is wavelength-dependent for narrow-band radiometers.
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Dark offset is internally temperature-compensated. |
PAR (LI-COR)
The RBRsolo³ PAR (LI-COR) instruments use cabled cosine (one hemisphere, LI-192) or spherical (omnidirectional, LI-193) PAR sensors.
Fig. 10. Cosine PAR sensor
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Fig. 11. Spherical PAR sensor
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RBRsolo³ PAR (LI-COR) variants
| Parameter | Value |
|---|---|
Wavelength range |
400 to 700nm |
Calibrated range |
0 to 10000µmol/m2/s |
Initial accuracy |
±2% |