SOX NOX AMBIENT ANALYSER

The APSA-370 Ambient SO₂ Monitor and the APNA-370 Ambient NOx Monitor are advanced continuous monitoring instruments designed for measuring atmospheric sulfur dioxide (SO₂), nitrogen oxides (NO, NO₂, NOx), and related pollutants with high accuracy.

Both analyzers use proprietary internal dry-method sampling technology, enabling continuous real-time analysis of gases in their natural state with minimal maintenance requirements. The dry-method system ensures long-term stability, high sensitivity, and reliable data unaffected by external moisture or interfering components.

These systems are ideal for use in ambient air monitoring networks, pollution control applications, and compliance reporting.

Common Features (APSA-370 & APNA-370):

Proprietary dry-method sampling system for high accuracy and low maintenance
Automatic ranging (manual or remote selectable)
Stable, repeatable measurements with high sensitivity
Built-in alarms for calibration errors, temperature deviations, and system faults
On-screen messages available in English, German, French, and Japanese
Input/Output options: 0–1 V / 0–10 V / 4–20 mA, contact input/output, and RS-232C
Compact design with robust construction for long-term use in field or fixed stations

APSA-370 (SO₂ Monitor) Additional Features:

UV-fluorescence detection principle for SO₂ monitoring
Moisture-resistant detector with selective membrane HC-cutter to eliminate interference
No supplemental gases required
Lamp intensity compensator ensures stable operation
Built-in inert PTFE sample inlet filter

APNA-370 (NOx Monitor) Additional Features:

Chemiluminescence detection (CLD) with cross-flow modulation
Simultaneous, continuous monitoring of NO, NO₂, and NOx
High-speed response with HORIBA’s silicon photodiode detector
Auto-recycle internal drier for dry air generation (ozone production)
Integrated O₃ drier unit, O₃ decomposer, reference gas generator, and sample pump

Parameter	APSA-370 (SO₂ Monitor)	APNA-370 (NOx Monitor)
Principle	UV Fluorescence (UVF)	Cross-flow modulated chemiluminescence (CLD)
Application	SO₂ in ambient air	NO, NO₂, NOx in ambient air
Standard Ranges	0–0.05/0.1/0.2/0.5 ppm	0–0.1/0.2/0.5/1.0 ppm
Optional Ranges	Up to 0–10 ppm (4 selectable ranges)	Up to 0–10 ppm (4 selectable ranges)
Repeatability	±1.0% of F.S.	±1.0% of F.S.
Linearity	±1.0% of F.S.	±1.0% of F.S.
Sample Flow Rate	Approx. 0.7 L/min	Approx. 0.8 L/min
Indication	Measured value, range, alarms, maintenance screen	Measured value, range, alarms, maintenance screen
Alarms	AIC, zero/span calibration errors, lamp/temp errors	AIC, zero/span calibration errors, converter/temp errors
Languages	English, German, French, Japanese	English, German, French, Japanese
Input/Output	Analog (0–1 V / 0–10 V / 4–20 mA), contact I/O, RS-232C	Analog (0–1 V / 0–10 V / 4–20 mA), contact I/O, RS-232C
Power Supply	100–240 VAC, 50/60 Hz (specify)	100–240 VAC, 50/60 Hz (specify)
Dimensions	430 (W) × 550 (D) × 221 (H) mm	430 (W) × 550 (D) × 221 (H) mm
Mass	Approx. 19 kg	Approx. 20 kg