CA2 Laboratory Thermopile - Radiant fluxes measurement
The CA2 thermopile measures radiant fluxes. It is sensitive to radiation from 0.2 to 50 µm and has a total field of view of 20°, determined by a cylindrical brass housing that contains a conical reflector and a removable glass window. The thermopile is very suitable for control (ovens) or demonstration (schools) purposes and can be used for reference-measurements.
- Spectral range (without window)
- 0.2 to 50 µm
- Spectral range (with window)
- 0.35 to 2.8 µm
- Sensitivity (parallel beam on front window)
- 7 to 20 µV/W/m²

Overview
In detail
How it works
The CA2 contains a thermopile detector with a spectrally non-selective black coating, so the detector responds to the total power absorbed.
The thermopile outputs a voltage in proportion to the radiation received.
Calibration
The thermopile is supplied with a calibration certificate.
Glass window
Irradiance measurements are easily affected by convection and thermal radiation losses to the environment. Therefore a glass window can shield the detector. By using this window, the spectral range is limited to 0.3 to 3 µm.
Applications
The CA2 laboratory thermopile is ideal for control purposes (such as ovens), demonstrations in schools and technical institutes, or to be used for reference measurements in optical laboratories.
The mounting rod allows easy fixing to standard optical bench fixing clamps. The terminals allow simple connection of bare wires or 4 mm banana plugs.
Reach out and say hi
Let us help. Tell us the site, the range you expect and what it has to talk to, and we’ll work out the right variant, cable and mounting — and quote it.
Specifications
Technical specifications
- Spectral range (without window)
- 0.2 to 50 µm
- Spectral range (with window)
- 0.35 to 2.8 µm
- Sensitivity (parallel beam on front window)
- 7 to 20 µV/W/m²
- Impedance
- 20 to 200 Ω
- Expected output range (0 to 1500 W/m²)
- 0 to 30 mV
- Maximum operational irradiance
- 2000 W/m²
- Response time (63%)
- < 6 s
- Response time (95%)
- < 18 s
- Non-linearity (100 to 1000 W/m²)
- < 1.5 %
- Field of view
- 20° (for 90% of the received radiation)
Ready to specify?
Add the CA2 to your enquiry
Build a list, add your site notes, and an ESS engineer will quote the lot — cables, mounting and calibration included.


