TSI DP-CALC 5815/5825 Portable Differential Pressure and Air Velocity Meter

Overview

The TSI DP-CALC 5815 and 5825 are precision-engineered portable differential pressure and air velocity meters designed for HVAC commissioning, building diagnostics, and indoor air quality (IAQ) assessments. Based on the fundamental principle of pitot-static tube measurement—where total pressure minus static pressure yields dynamic pressure—the instruments calculate airflow velocity using Bernoulli’s equation and a user-defined K-factor. Both models measure static and differential pressure across ducts, filters, coils, and dampers with high reproducibility and low drift. The 5825 extends functionality with automated volumetric flow calculation, time-stamped data logging, and integrated duct geometry input, enabling field engineers to perform ASHRAE Guideline 12–2020–compliant ventilation verification without external software or post-processing.

Key Features

• High-resolution pressure sensing: 0.001 in. H₂O (1 Pa) resolution with ±0.005 in. H₂O accuracy across the full −15 to +15 in. H₂O range
• Dual-mode operation: Simultaneous real-time display of differential pressure, static pressure, and derived velocity (when connected to a calibrated pitot tube)
• User-configurable time constant (0.1–10 s) for stable readings in turbulent or pulsating airflow conditions
• Statistical analysis functions: Min/max/avg/std dev for pressure and velocity over user-defined intervals
• Model 5825 exclusive capabilities: Volumetric flow computation (CFM or m³/h) based on entered duct dimensions, K-factor, and measured velocity profile; automatic area correction for round, rectangular, and irregular duct cross-sections
• Robust data management: On-device storage of up to 12,700 timestamped readings across 100 named data sets, with sampling intervals programmable from 1 second to 1 hour
• Integrated LogDat2 software suite included: Enables secure export, annotation, report generation, and audit-ready CSV/PDF output compliant with ISO/IEC 17025 documentation requirements

Sample Compatibility & Compliance

The DP-CALC series is compatible with industry-standard stainless steel pitot tubes (e.g., TSI Part No. 8760-01, 8760-02), static pressure probes, and flexible tubing assemblies meeting ASTM D5197–22 specifications for pressure tap integrity. It supports K-factor calibration for custom probe configurations per ANSI/ASHRAE Standard 111–2013. The instrument meets IEC 61000-4-2 (ESD immunity), IEC 61000-4-3 (radiated RF immunity), and RoHS 2011/65/EU directives. Its firmware architecture supports GLP/GMP-aligned workflows, including user access control, electronic signature prompts, and immutable audit trails when used with LogDat2 under FDA 21 CFR Part 11–configured environments.

Software & Data Management

LogDat2 software provides full traceability and regulatory readiness: each exported dataset retains embedded metadata—including instrument serial number, sensor calibration date, operator ID, ambient temperature/humidity (if logged via optional TSI 9565-P), and GPS coordinates (when paired with Bluetooth-enabled mobile devices). Data files are digitally signed and checksum-verified to prevent tampering. Batch reporting templates align with ASHRAE Technical Forms and ISO 16813:2006 indoor environment assessment frameworks. Firmware updates are delivered via encrypted USB or TSI Cloud Sync, ensuring continued compliance with evolving NIST-traceable calibration standards.

Applications

• HVAC system balancing and TAB (Testing, Adjusting, and Balancing) per NEBB Procedural Standards
• Fume hood face velocity verification and containment validation (ANSI/AIHA Z9.5–2022)
• Filter bank pressure drop monitoring for predictive maintenance scheduling
• Room pressurization checks in cleanrooms (ISO 14644-3) and healthcare isolation rooms (FGI Guidelines 2022)
• Combustion air intake and exhaust stack flow characterization
• Energy audit pre- and post-retrofit airflow quantification (IPMVP Option B)

FAQ

What is the difference between the DP-CALC 5815 and 5825 models?

The 5815 is a dedicated differential/static pressure and velocity meter with statistical functions. The 5825 adds volumetric flow calculation, programmable duct geometry input, automated data logging with timestamps, and expanded memory capacity.
Can the DP-CALC be used with third-party pitot tubes?

Yes—provided the tube’s K-factor is known and entered manually; however, optimal accuracy is achieved using TSI-certified pitot tubes calibrated against NIST-traceable wind tunnel standards.
Is the instrument suitable for outdoor or high-humidity environments?

It operates reliably from 0–70 °C and up to 95% RH non-condensing; for extended outdoor deployment, use with a protective carrying case and avoid direct solar exposure during measurement.
How is calibration maintained over time?

TSI recommends annual recalibration against a certified deadweight tester or primary standard manometer; onboard zero-stability verification is supported via built-in auto-zero function before each measurement session.
Does LogDat2 support multi-user environments with role-based permissions?

Yes—administrators can define read-only, operator, and calibration technician roles with password protection and activity logging enabled by default.