Class A pyranometer CMP21

analogvoltage output4-20 mA

Overview
The Kipp & Zonen CMP21 is a research-grade pyranometer compliant with ISO 9060:2018 Spectrally Flat Class A. It measures global irradiance on a plane surface (W/m²) from direct and diffuse solar radiation. The CMP21 uses the same detector as the CMP10, with individually optimized temperature compensation and a standard thermistor for housing temperature monitoring. Each unit is delivered with individual temperature and directional (cosine response) test data, making it suitable for scientific networks and high-accuracy monitoring installations.

Key features

• Spectrally Flat Class A (ISO 9060:2018)
• Detector shared with CMP10 with optimized temperature compensation
• Standard thermistor for housing temperature monitoring
• Supplied with individual temperature and directional test data
• Integrated waterproof socket for Kipp & Zonen yellow signal cable and waterproof plug
• Raised integral bubble level visible without removing snap-on sun shield; sun shield covers connector
• Screw-in external drying cartridge; replacement desiccant in refill packets
• No dedicated power supply required — analogue low-voltage output approx. 0 to 21 mV (0 to 1500 W/m²)
• Optional AMPBOX for higher voltage levels or 4–20 mA signal

Technical specifications

• Classification: Spectrally Flat Class A (ISO 9060:2018)
• Analogue output: 0 to 21 mV for 0 to 1500 W/m²
• Zero offset A: < ±7 W/m²
• Zero offset B: < ±2 W/m²
• Directional response: < ±10 W/m² (up to 80° @ 1000 W/m² beam)
• Non-linearity: < ±0.2% (100–1000 W/m²)
• Non-stability: < ±0.5% change/year
• Spectral range (accuracy): 285–2800 nm
• Response time: < 1.7 s (63%), < 5 s (95%)
• Operating temperature range: -40 to +80 °C
• Operating humidity: 0–100%
• IP rating: IP67
• Weight: 600 g (1.3 lb)
• Material: Anodized aluminum enclosure
• Cable length options: 10, 25, 50, 100 m
• Drying cartridge: External; replacement approx. every 6 months
• Irradiance saturation (max): 4000 W/m²
• Sensitivity: 7–14 µV/W/m² (< ±1% between -20 and +50 °C)
• Temperature correction: < ±1% (-20 to +50 °C)