Menu Close

ST DNI-01 Pyrheliometer

Make: Schelt Technology                                      Model: ST DNI-01
✅ Sensor is used to measure the radiation perpendicular to the sun’s  surface and the diffuse radiation around the sun.
✅ Measurand: DNI.
✅ Sensor Type: Thermopile.
✅ Signal Output: Analog (0-5V, 4-20mA)
✅ Supplied With: 2.5 m, with Connector At Instrument End

ST DNI-01 Pyrheliometer:

The standard direct radiation sensor is used to measure the radiation perpendicular to the sun’s surface and the diffuse radiation around the sun. It has the function of automatically tracking the sun and monitoring the direct radiation of the sun. The sensor is mainly composed of a light cylinder and an automatic tracking device. The inner part of the optical cylinder is composed of seven light bars and inner cylinders: quartz glass, a thermopile, and a desiccant cylinder. The seven-light barrier is used to reduce the internal reflection, form the open angle of the instrument, and limit the turbulence of the air inside the instrument.

Outside the light barrier, the inner cylinder is used to seal the dry air inside the light rail, and the outer cylinder is used to reduce the influence of the ambient temperature on the thermopile. JGS3 quartz glass is installed on the cylinder, and it can radiate directly through the 0.3–3 m wavelengths. The end of the barrel is equipped with a desiccant to prevent the condensation of water vapor.

The sensing part is the core component of the optical cylinder. It is composed of a fast-response wire-wound, electroplated multi-node thermopile. The sensing part facing the sun is coated with American 3M black paint, which is a thermal junction of the thermoelectric reactor. When the sun is exposed, the temperature rises, and it forms an electromotive force with the other cold junction. The electromotive force is proportional to the intensity of the solar radiation.

The automatic tracking device is composed of a bottom plate, a latitude frame, an electric motor, a conductive ring, a worm gear box (used for adjusting the sun inclination angle), and a motor controller. The driving part is controlled by a single chip microcomputer, and the power supply is DC 12V. The accuracy of the motor is high, and the angle error is less than 0.25 deg within 24 hours.
When the latitude is adjusted to the local geographic latitude, the black line on the floor is coincided with the south north line, and the angle of the dip is the same as that of the sun at that time, and the accurate automatic tracking can be achieved.

Application and features of ST DNI-01 Pyrheliometer:



✅ Scientific meteorological
✅ Climate observations
✅ Material testing research
✅ Assessment of the efficiency of solar collectors and photovoltaic devices.
✅ Optical window for broad bandwidth and superior durability
✅ Powder coated aluminum for corrosion resistance
✅ Compact size and light weight.

Schelt Technology



Weight (Mass)

0.5 kg


0-2.5V or 0-5V

Power Supply

12 VDC

Measuring Range

0 – 2000 W/m²

Operating Environment

-40…+70°C / 0…100% Rh

Spectral Range


Temperature Response

± 1% (-10 to +40°C)

Response Time 95%

< 25 s





Protection Level

Sealed To IP66

Quote ST DNI-01 Pyrheliometer