The KOBOLD DRS is a compact turbine flow meter for liquids, designed for OEM applications that need a quality flow measurement solution at an economical price. It measures 0.6 to 10.5 GPM (2.3 to 39.7 L/min) of water with an accuracy of ±1.5% of full scale, and it is offered in PPO plastic, brass, and 304 stainless steel body versions with pulse frequency, 4-20 mA analog, or switching outputs. An optional Pt-100 RTD adds temperature measurement alongside flow. The DRS is made in the USA.
Design of the DRS Compact Turbine Flow Meter
The DRS pairs a vane-axial turbine wheel with embedded permanent magnets and a Hall effect sensor in a body with an installed length of 3.14 in (80 mm). Because the magnetic pickup does not rely on optical clarity, the sensor meters clear and opaque liquids alike.
The rotating vane is sapphire-supported, which helps ensure a high degree of linearity and long service life. Wetted materials depend on the version: PPO, PEI, NBR, sapphire, and 316 stainless steel for the plastic body; brass, PEI, NBR, sapphire, and 316 stainless steel for the brass body; and 304 stainless steel, PEI, FKM, sapphire, and 316 stainless steel for the stainless steel body.
Performance and Ratings
Standard versions measure with an accuracy of ±1.5% of full scale, a linearity of ±0.5% of full scale, and a repeatability of ±0.1% of full scale; the OEM DRS-..K0000 version is rated at ±5% of full scale. Metal sensors deliver 384 Hz at 10.5 GPM, and plastic sensors deliver 352 Hz.
Brass and stainless steel bodies are rated to a maximum operating pressure of 2900 PSIG (200 bar), while the PPO plastic body is rated to 230 PSIG (15.9 bar). The standard temperature range is -4 to 176°F (-20 to 80°C), and silicone-cable S versions for the brass and stainless steel sensors extend the maximum to 300°F (149°C). Protection is IP 65 with the plug connector and IP 66 with a cable outlet, and standard versions conform to the EMC and RoHS directives while dedicated OEM versions ship without a CE mark.
Output and Electronics Options
Five output families are available: OEM Hall-signal versions with cable outputs, PNP pulse frequency versions, 4-20 mA analog versions in 2-wire or 3-wire form, and two compact electronics versions that add a 3-digit LED display with switching contacts. A 2-wire Pt-100 RTD can be added to selected outputs for temperature measurement.
OEM versions DRS-..K0000, S0000, and S000P deliver a direct NPN signal from the Hall sensor over a factory-fitted PUR or silicone cable. DRS-..F300 and F500 supply a PNP open collector pulse output, while DRS-..L.. versions supply 4-20 mA with a maximum load of 500 Ω and a t90 response time of 25 s on brass and stainless steel sensors or 100 s on PPO sensors. DRS-..C30R adds two programmable PNP or NPN switching contacts, DRS-..C34P combines an adjustable 4-20 mA output with one switching contact, and both compact electronics versions are configured with two buttons.
Process Connections and Installation
Connection options depend on the body material: brass offers five thread choices, including the only 1/2" NPT female option, while the stainless steel and PPO plastic versions use 3/4" NPT male or G-style threads. The DRS installs in horizontal pipes or in vertical pipes with ascending flow, always in the direction of the arrow.
Piping should be secured approximately 2 in (50 mm) away from the connections so that the threads are not subjected to pressure or tensile loading, and flat seals are the preferred sealing method. When a pre-assembled angled M12x1 connection cable is used, the cable outlet always aligns opposite the flow direction.
Applications of the DRS Turbine Flow Sensor
Typical applications include washing machines, vehicles, farm equipment, photograph development machines, and the printed-circuit board industry. The DRS is designed for OEM use in applications such as these, and each body material, connection, and output option is selected through a single ordering code.
Flow Direction Specification May Be Required
Important: This flow meter (model dependent) may require flow direction specification to complete your order.
While our product number identifies the meter's core specifications, flow direction is a critical parameter for certain models that must be specified separately to ensure proper performance and installation.
Why Flow Direction Matters
Flow meters are precision instruments engineered with internal components optimized for fluid movement in a specific direction, for certain models. Installing a meter that requires flow direction with an incorrect flow direction will not allow it to function properly.
What We Need From You
Please read the datasheet order table carefully (including any asterisks) and if your model requires a flow direction please specify your desired flow direction, in addition to your part number, when placing your order.
Flow directions are option/model-dependent but may include the following choices:
- Top to Bottom
- Bottom to Top
- Left to Right
- Right to Left
We cannot process orders without the required flow direction specification, if it is needed. Orders submitted that are missing this information are likely to experience delays in processing.
If you're unsure of your flow direction, our technical team is ready to assist you in determining the correct specification based on your system requirements at 412-788-2830 or customerservice@koboldusa.com.
Important Notice: Transitioning to U.S. Manufacturing
Due to the ongoing implementation of EU Directive 2020/2184 that restricts brass materials, product availability is subject to change at any time. We are actively reshoring production of our brass flowmeter models to U.S. facilities to ensure continued supply. Not all products can/will be reshored. During this transition, stock availability may fluctuate between the time of quotation and purchase order placement. We appreciate your patience as we work to establish our domestic supply chain and remain committed to providing you with the same high-quality products made closer to home.
Common Questions about DRS - Turbine Flow Sensor
The DRS operates on the turbine wheel principle. Liquid first passes through a laminar flow element that eliminates turbulence and routes the stream into the turbine wheel. Rotation is sensed without contact through magnets embedded in the wheel, and the resulting frequency signal is proportional to the flow velocity.
Standard versions (DRS-9180, DRS-9280, DRS-9380) carry the full output and electronics range with an M12x1 plug connector. OEM versions (DRS-0180, DRS-0280, DRS-0380) are supplied without a CE mark and deliver the NPN frequency signal from the Hall sensor directly over a fixed PUR or silicone cable.
Yes, a 2-wire Pt-100 RTD option adds temperature measurement alongside the flow signal. On standard versions it is available with the F300, F500, and L343 outputs, and on OEM versions through the S000P code. It is not offered with the K0000 output or the compact electronics versions.
Supply requirements depend on the output electronics: 5-24 VDC for the OEM K0000 and S0000 versions, 12-28 VDC with about 10 mA consumption for the F300 and F500 pulse versions, and 24 VDC ±20% for the 4-20 mA analog versions and both compact electronics models.
A complete part number combines the model, connection, and output codes, for example DRS-9180 N5 F300: a brass body (9180) with a 3/4" NPT male connection (N5) and PNP frequency output (F300). Add ..P for the Pt-100 option. Flow direction must be stated in writing for meters configured with a compact electronics option.
The brass DRS offers the widest choice: 1/2" NPT female, 3/4" NPT male, G 1/2 female, G 1/2 male/female, and G 3/4 male. Stainless steel and PPO plastic bodies are supplied with 3/4" NPT male, G 1/2 male/female, or G 3/4 male thread connections.
As long as the metered liquid is not polluted, the measuring unit is maintenance-free, and installing a magnet filter such as the KOBOLD MFR helps avoid problems. If cleaning becomes necessary, uninstall the sensor and rinse it thoroughly in clean water. Only the supplier may work on the electronics, keeping the warranty valid.
Mating connectors with 6 ft cables are offered for both plug styles: model 807.037 (4-pin Micro-DC) for the F300, F500, L342, and L343 outputs, and model 807.007 (5-pin) for the C30R and C34P versions. The AUF-1000 and AUF-1001 plug-on displays give the DRS-..L442 a 4-digit LED readout.