Cole-Parmer 32707-00 Thermal Mass Flowmeter / Flow Transmitter

Overview

The Cole-Parmer 32707-00 is a compact, cost-optimized thermal mass flowmeter designed for precise, real-time measurement of gas flow rates in laboratory, pilot-scale, and light industrial applications. It operates on the principle of constant-temperature anemometry (CTA), where a heated sensor element and a reference sensor are exposed to the gas stream; the differential cooling effect—proportional to mass flow rate—is converted into a linear 0–5 VDC analog output signal. Unlike volumetric or differential pressure-based devices, this instrument measures true mass flow without requiring temperature or pressure compensation, delivering inherently stable readings across varying ambient conditions. Its low-pressure-drop design minimizes system backpressure, making it suitable for sensitive gas delivery systems, glove boxes, environmental chambers, and analytical instrumentation interfaces. The device is factory-calibrated using dry air or nitrogen traceable to NIST standards, with optional custom calibration available for other gases—including argon, CO₂, helium, and binary mixtures—upon request through authorized distributors.

Key Features

• Thermal mass flow sensing technology ensures direct, temperature-compensated mass flow measurement without external correction algorithms.
• Low-profile, portable form factor (approx. 3.5″ × 2.5″ × 1.2″) enables integration into space-constrained setups or field-deployable monitoring stations.
• Two configuration options: bare transmitter (no display) or integrated 3½-digit LCD with 90° tilt adjustment for ergonomic viewing under varied mounting angles.
• Standard 0–5 VDC linear output compatible with data acquisition systems (DAQ), PLCs, SCADA controllers, chart recorders, and OEM instrumentation interfaces.
• Modular wetted path construction: anodized aluminum body standard; select models feature 316 stainless steel fittings for enhanced corrosion resistance and compatibility with aggressive process gases.
• Robust electrical interface via hub-style connector—simultaneously delivers power and transmits analog output over a single 36″ (0.9 m) shielded cable.
• Optional rechargeable battery kit (Cat. No. 32707-70/75) supports >8 hours of continuous operation and >500 charge cycles, enabling true cordless portability.

Sample Compatibility & Compliance

The 32707-00 is validated for use with clean, dry, non-corrosive gases such as air, nitrogen, oxygen, argon, helium, and carbon dioxide. Particulate content must remain below 20 µm to prevent sensor fouling. For applications involving reactive, condensing, or high-humidity gases, optional filtration and conditioning modules are recommended upstream. All units comply with CE marking requirements for electromagnetic compatibility (EMC Directive 2014/30/EU) and low-voltage safety (LVD Directive 2014/35/EU). While not certified for hazardous locations, the device meets general-purpose laboratory safety expectations per UL 61010-1 and IEC 61010-1. Calibration documentation includes NIST-traceable certificates for air/N₂; custom calibration reports for alternate gases adhere to ISO/IEC 17025-accredited procedures when performed by Cole-Parmer’s metrology lab.

Software & Data Management

As a standalone analog transmitter, the 32707-00 does not include embedded firmware or digital communication protocols (e.g., Modbus, RS-485). Its 0–5 VDC output is engineered for seamless integration into existing analog infrastructure. Users deploying the meter in regulated environments (e.g., GLP, GMP, or FDA 21 CFR Part 11-compliant workflows) must implement external data logging systems that provide audit-trail functionality, electronic signatures, and secure data storage. When paired with compliant DAQ hardware (e.g., National Instruments USB-6009 or Keysight 34972A), the device supports full traceability—including timestamped flow records, calibration history, and operator metadata—required for quality assurance documentation.

Applications

• Gas flow verification in laboratory fume hoods and ventilation safety systems.
• Mass flow monitoring in gas chromatography carrier gas lines and purge-and-trap sample introduction systems.
• Process validation of inert gas blanketing in pharmaceutical reaction vessels and lyophilizers.
• Leak testing support via controlled gas injection and downstream flow quantification.
• Educational labs for teaching fluid dynamics, sensor physics, and control system interfacing.
• OEM integration into breath analyzers, environmental sensors, and gas blending manifolds.

FAQ

Is the 32707-00 suitable for measuring humid or corrosive gases?
No—this instrument is rated only for clean, dry, non-aggressive gases. Exposure to moisture, solvents, or acidic gases may degrade the thermal sensor or Viton® seals. Install appropriate coalescing filters and desiccant dryers upstream if ambient gas contains condensable vapor.
Can I recalibrate the unit for a gas other than air or nitrogen?
Yes. Cole-Parmer offers certified multi-point recalibration services for common industrial gases (e.g., CO₂, Ar, He, O₂) and custom mixtures. Contact technical support to initiate a calibration request with gas composition and required uncertainty specifications.
What is the minimum load impedance required for the 0–5 VDC output?
The output requires a minimum load impedance of 2500 Ω to maintain specified linearity and accuracy. Lower impedances may introduce signal attenuation and measurement drift.
Does the flowmeter include mounting hardware or installation instructions?
Each unit ships with two compression fittings (size dependent on model), a 36″ hub-connector cable, and basic mechanical installation guidelines. Detailed piping schematics and torque specifications are provided in the product manual (PN: 32707-MAN).
Is firmware or driver software included?
No. As an analog-only device, no drivers, SDKs, or configuration utilities are supplied. Integration relies solely on hardware-level voltage signal interpretation by the connected receiving system.