Flow Metering
Greyline PDFM 5.1 Portable Doppler Flow Meter
Portable Doppler flow meter designed for accurate flow measurement in full pipes containing suspended solids or aeration.
Max Flow Rate
L / h
Max Discharge Pressure
Barg
Max Air Supply Pressure
Barg
The Greyline PDFM 5.1 Portable Doppler Flow Meter is a robust, handheld device engineered for rapid, non-intrusive flow measurement in closed, full pipes containing liquids with suspended solids or entrained air bubbles. It’s ideal for troubleshooting, flow balancing, and verifying performance of in-line meters — without cutting the pipe or interrupting flow.
This advanced portable Doppler unit measures flow velocity using reflected ultrasonic signals from solid particles or gas bubbles in the fluid stream. It provides reliable readings in difficult applications where conventional meters fail.
Key Features
- Non-invasive Doppler technology — no pipe cutting or process interruption
- Measures flow in full pipes with suspended solids or aerated liquids
- Installs and calibrates in minutes using the built-in 5-key menu
- Portable design with rechargeable NiMH battery (18-hour operation)
- Built-in 300,000-point data logger with USB connectivity
- Large backlit display showing flow rate, total, and diagnostics
- Adjustable damping and sensitivity for noisy applications
- Compatible with most pipe materials — steel, PVC, HDPE, lined ductile iron, etc.
- Supplied in IP67-rated case with stainless steel pipe clamp and couplant
- Optional 15 m sensor extension cable and extra clamps available
Applications
- Temporary or permanent flow monitoring
- Pump and system performance testing
- Wastewater, sludge, or slurry flow measurement
- Verification of in-line flow meters
- Flow balancing in treatment works and industrial plants
Technical Specifications
- Measurement principle: Ultrasonic Doppler (reflected signal method)
- Flow range: ±0.46 m/s to 12.2 m/s (±0.125 to 40 ft/s)
- Pipe size range: 12.7 mm to 4.6 m (0.5 in to 15 ft)
- Minimum particle size: 100 microns (75 ppm concentration)
- Accuracy: ±2% of reading or ±30 mm/s (1.2 in/s)
- Repeatability: ±0.1% | Linearity: ±0.5%
- Operating temperature (electronics): –23 °C to +60 °C
- Sensor temperature: –40 °C to +150 °C
- Transducer: Clamp-on single-head (PSE4), 3.4 m (12 ft) cable
- Outputs: 4–20 mA (AC powered), USB for data transfer
- Data logger: 300,000 data points, time and date stamped
- Display: White backlit matrix LCD showing flow, total, and status
- Enclosure: Portable ABS housing, IP67-rated carry case
- Power: Internal NiMH battery, 18-hour runtime, 100–240 V AC charger
- Approvals: CE, CSA, UL, EN 61010-1
Why Choose the PDFM 5.1
The PDFM 5.1 provides fast, accurate flow readings for liquids with entrained solids or gases where other technologies struggle. It’s lightweight, easy to install, and perfect for engineers needing portable diagnostics in industrial, wastewater, or sludge-handling systems.
A Complete Chemical Injection Package Built Around Your Needs
Every chemical injection package we build can be tailored to your exact process requirements. Alongside the pump skid, PPM supplies all essential equipment from the suction point through to final discharge so you receive a fully integrated, ready-to-operate solution. A typical package can include items such as suction and discharge hoses, discharge manifolds with non-return valves, chemical tanks, bunded drum trolleys, and drip trays, all selected to suit the application.
Complete Fluid Transfer Solutions Built Around Your Needs
PPM’s fluid transfer systems are designed to give you consistent performance in challenging conditions. Each build can be adapted to suit your required flow rates, pressures, materials, and connection types, ensuring a seamless fit within your existing process. Our engineers can integrate the correct hose assemblies, manifolds, couplings, and protective measures so your equipment arrives ready to operate from day one.
Accurate Flow Metering Packages Built for Precision and Compliance
Our flow metering packages are configured to give you dependable accuracy, full compliance, and ease of integration. Systems can be built around your preferred metering technology and calibrated to the exact characteristics of the process stream. PPM will supply the required pipework, fittings, valves, supports, and instrumentation so the complete assembly is delivered as a clean, fully engineered unit ready for installation.
We Supply Diaphragm Pumps from Any Manufacturer, Including the Brands Below
In high-stakes environments, reliability isn’t optional — it’s the baseline. Every piece of PPM equipment is backed by rigorous testing, full traceability, and direct access to the people who built it. From the first conversation to final sign-off, our process is designed to remove uncertainty and deliver equipment you can trust to perform under pressure.
Certification with Every Unit
Every product is supplied with complete documentation, serial numbers, and test records — so you know exactly what you’re working with, every time.
Proven Before It Leaves Us
We run each unit through inspection and performance testing against your spec, ensuring it meets or exceeds requirements before shipping.
Speak to the Experts, Not a Call Centre
Our engineers are on hand for setup, troubleshooting, and technical advice — so you get answers fast, from the people who know the kit inside out.
Trusted Across Industries
Our solutions are relied on by leaders in oil & gas, manufacturing, agriculture, and more — with a history of delivering results in demanding conditions.
Bespoke PPM Packages Backed by Real-World Performance
Real-world examples of hire and service solutions keeping plants and platforms online.
Whether it’s an urgent replacement or a planned upgrade, our team will get your equipment on site fast and operational without delay.