D118 · Fixed flow

Industrial flow. Wired into your controls.

Continuous flow measurement for industrial systems, with RS485 (Modbus), 4–20 mA, pulse and relay outputs. Available in clamp-on and insertion configurations.

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At a glance

What D118 does, in plain words.

What it measures: Liquid flow; How much liquid moves through the pipe.
How it installs: Clamp-on or insertion; Clamp-on sensors fit outside the pipe. Insertion versions go through the pipe wall.
How it connects: RS485 / 4–20 mA; Wired into control systems over Modbus RS485, or as a 4–20 mA signal.
Pipe sizes: DN25–DN5000; DN is the nominal pipe size, roughly the inside diameter in millimetres.

Why D118

D118 in short.

D118 is a transit-time ultrasonic flowmeter for continuous measurement of homogeneous liquids in industrial settings, with clamp-on or insertion sensors.

It has a window-style interface with metric and imperial units, logs data to a TF card for more than 1000 days and connects over RS485 (Modbus) with 4–20 mA, pulse and relay outputs.

0.5% accuracy under standard conditions
Clamp-on or insertion sensors for 25–5000 mm pipes
RS485 Modbus plus 4–20 mA, pulse and relay outputs
TF-card logging for more than 1000 days
IP65 transmitter, IP68 sensors

Where it is used

Municipal engineering
Industrial and commercial water metering
Water and wastewater management
HVAC systems
Chemical, pharmaceutical, food and beverage processes
Energy management and environmental monitoring
Agriculture and irrigation
Facilities management

D118 with clamp-on sensors on copper pipe

How it works

Sound with the flow arrives sooner.

Two sensors on the same side of the pipe take turns sending sound through the water. Sound travelling with the flow arrives slightly sooner than sound travelling against it; the meter turns that time difference into flow, which is why it needs to know your pipe.

How clamp-on ultrasonic measurement works →

Pipe & installation

What the meter needs to know about your pipe.

These are set up on the meter after installation. Pipe size and transducer type are decided when ordering.

Pipe & installation guide pipe materials, sizes, setup checklist

Stainless steel · 2″ example

A smooth metal surface. Clean the spot, add coupling gel, then clamp the sensor on.

60.3mmacross the outside

2.8mmwall thickness

54.8mmacross the inside

Pipe sizes are names, not measurements: a 2″ pipe is 2.375″ across.

The meter needs Pipe size Wall thickness Material: Stainless steel

Technical details standards, OD / ID, both units

Standard: ASME B36.19 · 2″ Sch 10S
Outside diameter (OD): 2.375″ (60.33 mm)
Wall: 0.109″ (2.77 mm)
Inside diameter (ID): 2.157″ (54.79 mm)
Meter parameters: OD · wall · material

This guide shows what a clamp-on meter needs to know about a pipe. It does not mean every model fits every pipe: check the specifications below or ask an engineer.

Specifications

Check the fit before you specify.

The short version is above. These are the specifications published for D118; values that are still being checked are left out.

Performance

Measurement: Continuous liquid flow
Flow velocity: ±0.01 to ±12 m/s (±0.03 to ±40 ft/s)
Accuracy: 0.5% (0.5–5 m/s, standard conditions)
Repeatability: 0.1%
Pipe size, clamp-on: 25–5000 mm (1″–200″)
Pipe size, insertion: 50–5000 mm (2″–200″)
Medium temperature: −40 °C to 80 °C (standard)
Pipe material: Carbon steel, stainless steel, cast iron, ductile iron, copper, PVC, aluminium, asbestos, fibreglass-epoxy

Function

Outputs: 4–20 mA (max. load 750 Ω), pulse 0–9999 Hz (OCT), relay (max. 1 Hz)
Communication: RS485 and RS232 with Modbus protocol
Data storage: TF card, more than 1000 days; interval 1–3600 s
Power supply: 90–245 VAC (48–63 Hz) or 10–36 VDC
Keypad: 24-key touch keyboard
Display: 3.71-inch TFT colour screen
Ambient temperature: −10 °C to 50 °C
Humidity: Up to 99% RH, non-condensing

Physical

Transmitter: Die-cast aluminium, IP65
Sensors: Sealed, IP68; cable 9 m standard, extendable to 305 m
Weight: Transmitter about 2.2 kg; clamp-on sensors about 2 kg per pair; insertion sensors about 4 kg per pair

Need a value that is not listed, or the datasheet for your configuration? Ask an engineer.

What these terms mean

DN: Nominal pipe size, roughly the inside diameter in millimetres (DN50 ≈ 50 mm).
Clamp-on: Sensors strap to the outside of the pipe. No cutting, no shutdown for installation.
PoE: Power over Ethernet: one network cable carries power and data.
LoRaWAN: Long-range, low-power wireless. Readings travel through a gateway to a network server.
Modbus RS485: A wired connection widely used by building and industrial control systems.
4–20 mA: An analogue signal where the current represents the reading.