GPR-1500

Supported Applications

The Aii GPR-1500 series comprises PPM Oxygen Transmitters and Analyzers engineered for oxygen analysis in inert, hydrocarbon, helium, hydrogen, mixed, and acid (CO₂) gas streams. These instruments are designed for general purpose use as well as hazardous area installations requiring specific safety certifications.

The series supports measurement of trace oxygen concentrations across a broad envelope, utilizing electrochemical sensor technology optimized for clean gases and environments containing carbon dioxide or acidic components.

Operating Conditions & Performance

Performance specifications vary by model configuration. The GPR-1500 series offers analysis ranges including 0–10 PPM, 0–100 PPM, 0–1000 PPM, and 0–1% O₂, with a dedicated 0–25% range available for air calibration. Accuracy is specified as < 2% of full scale (FS) range under constant conditions.

The series provides resolution down to 0.01 PPM and linearity within ±1% or ±2% of FS depending on the specific model variant. Response time varies by configuration: general purpose models achieve 90% of final reading in 10 seconds, while hazardous area certified variants with liquid drain manifolds may require < 2 minutes for 90% response.

Operating temperature ranges differ based on sensor selection:

• GPR sensors: +5°C to +45°C
• XLT sensors (for CO₂/acidic gases): -10°C to +45°C or -18°C to +45°C depending on the specific hazardous area rating.

Inlet pressure must be regulated to 5–30 psig to deliver a recommended flow rate of 1–2 SCFH. The analyzers are not flow-sensitive within this range but require atmospheric venting.

Configuration Options

The GPR-1500 series is configurable across several dimensions including hazardous area certification, sample conditioning, sensor type, and output signals.

Hazardous Area & Enclosure Options

• General Purpose: Fiberglass NEMA 4X enclosure (6.75 x 8.375 x 4.25 inches).
• Hazardous Area Certified: Models available with cMETus, ATEX, IECEx, and UKEX certifications for Class I, Division 1, Groups C & D or Zone 0/Zone 1 applications.
• Enclosure Ratings: NEMA Type 3R (rain resistant) or NEMA 4X depending on the certification path; housings constructed from fiberglass and painted aluminum.

Sensor & Media Compatibility

• GPR-12-333: Standard PPM sensor for non-acid gas streams.
• XLT-12-333: Designed for gases containing > 0.5% CO₂ or acidic background gases.
• GPR-12-333-H: Optimized for H₂ and He background gases.
• Liquid Drain (LD) Option: Unique liquid drain sensor manifold available on specific hazardous area models to manage condensate.

Outputs & Power

• Analog Output: 4–20 mA or optional 1–5V DC (non-isolated).
• Digital Communication: Optional Modbus RTU communication.
• Power Supply: Configurable for 12–28 VDC, 18–24 VDC (loop powered), or 110–220 VAC depending on the hazardous area certification and model variant.

Sample Conditioning & Accessories

• Inlet Fittings: 1/8" compression tube fittings (general purpose) or 1/4" compression tube fittings (liquid drain models).
• Filtration: Optional A-4442 coalescing filter assembly fitted on the inlet.
• Sample Panels: Automated sample conditioning systems available as separate options.

Key Product Differences

The series distinguishes between general purpose and hazardous area configurations through specific model suffixes and ordering codes. The GPR-1500 base models are 4-wire powered transmitters, while the GPR-1500A variants function as industrial analyzers with expanded output options including Modbus.

Key distinctions include:

• GPR-1500 (General Purpose): Features a fiberglass NEMA 4X enclosure, 1/8" tube fittings, and standard sensor configurations. Response time is typically < 2 minutes for hazardous variants with liquid drain manifolds versus 10 seconds for general purpose models.
• GPR-1500 IS-LD / AIS-LD: Hazardous area certified versions featuring a unique liquid drain sensor manifold, NEMA Type 3R or NEMA 4X enclosures (depending on UL/ATEX path), and specific power requirements such as 18–24 VDC for loop-powered configurations.
• Sensor Selection: The choice between GPR-12-333, XLT-12-333, or GPR-12-333-H sensors dictates compatibility with CO₂, acidic gases, hydrogen, and helium environments.
• Housing Material: While general purpose models utilize fiberglass NEMA 4X housings, hazardous area variants may employ stainless steel wetted parts within enclosures rated for outdoor or indoor industrial use.