The KOBOLD DPM is a compact paddle wheel flow sensor that uses a pelton wheel, a specific type of paddle wheel technology, to measure low flow rates of water and water-based, optically transparent liquids. Seven ranges span 0.24–4.8 GPH up to 0.8–80 GPH, with nickel-plated brass or 316L stainless steel bodies, pulse frequency or 4-20 mA analog outputs, and optional switching and display electronics. The sensor is rated to 230 PSIG (15.9 bar) and 176 °F (80 °C), carries IP 65 electrical protection, and needs no inlet or outlet straight piping, so it can be mounted in any orientation with the axle in the horizontal plane.
How the DPM Measures Flow
Liquid enters through a nozzle at the inlet of the flow body and is directed onto a flat-blade pelton turbine that rotates at a speed proportional to flow rate. An optical sensor detects the rotation without contact, and the electronics process it into an amplified pulse or 4-20 mA signal.
- The vane is sapphire-supported, which is designed to provide a high degree of linearity and long service life.
- A frequency divider with pulse output is available as an option.
- Because the nozzle redirects the incoming flow, the sensor requires no straight piping upstream or downstream.
Flow Ranges, Accuracy, and Pressure Drop
The DPM covers seven water flow ranges: 0.24–4.8, 0.8–11.1, 0.8–15, 0.8–30, 0.8–48, 0.8–60, and 0.8–80 GPH. Accuracy is ±1.5% of full scale for the 4-20 mA and compact electronics versions and ±2.5% of full scale for the K000 and F300 frequency outputs.
- Pressure drop at maximum flow runs from 8.3 psi on the larger ranges to 17.7 psi on the 0.8–15 GPH range.
- Output frequency at maximum flow ranges from 165 Hz to 439 Hz depending on the model.
Construction and Materials
The flow body is offered in nickel-plated brass or 316L stainless steel, identified by the model number. Wetted internals combine a 316L stainless steel nozzle, a sapphire axle and bearing assembly, a polypropylene pelton wheel, and a polysulfone receiver, with an NBR O-ring on brass housings and FKM on 316L stainless steel housings.
- Electrical protection is rated IP 65.
- Compact electronics versions use a 304 stainless steel electronics housing.
- Made in the USA; BABA (Build America, Buy America) compliant models are available.
Outputs, Electronics, and Displays
Six output configurations cover OEM integration through stand-alone monitoring: two frequency outputs, two 4-20 mA analog outputs, and two compact electronics packages with a 3-digit LED display and PNP switching. A plug-on 4-digit LED display is available for the DIN-plug analog version.
- K000: OEM frequency output, NPN open collector (10 mA max.), 4.5–12 VDC supply, 5 ft PVC cable.
- F300: frequency output, PNP open collector (25 mA max.), 24 VDC ±20%, M12 Micro-DC plug.
- L343 and L443: 4-20 mA, 3-wire, 500 ohm maximum loop load, 24 VDC ±20%, with Micro-DC or DIN 43650 plug.
- C34P and C30R compact electronics: 4-20 mA output with one PNP switch, or two PNP switches, 300 mA max. short-circuit protected, programmable for span, switching point, and lockout code.
- AUF-3000 plug-on display for the L443: 4-digit LED, powered through the analog output. Mating connector cables are available as accessories (807.037 for F300/L343; 807.007 for C34P/C30R).
Installation and Maintenance
The DPM mounts in the line with flow in the direction of the arrow and requires no maintenance when the measured medium is clean. Inlet and outlet lines are fixed mechanically about 2" (50 mm) from the connections to keep pressure and tensile loads off the sensor.
- Operating above the rated range can damage the bearings and cause major measuring errors.
- Installing a filter such as the KOBOLD MFR magnetic filter is recommended to prevent coating of the sensor optics.
- The sensor can be opened for cleaning without damaging the blades, and the vane goes back in its correct position on reassembly. Work on the sensor and electronics is reserved for the supplier, otherwise the guarantee is nullified.
- With a pre-assembled M12x1 angled-plug cable, the cable outlet aligns opposite the flow direction.
Compliance
The DPM falls under sound engineering practice per Article 4, Paragraph 3 of Pressure Equipment Directive 2014/68/EU and carries no CE mark under that directive. The series conforms to RoHS Directives 2011/65/EU and 2015/863/EU, and versions with electronics meet EMC Directive 2014/30/EU per EN IEC 61326-1:2021, with UK declarations in place.
Evergreen notice blocks — preserved VERBATIM (part of the same Description paste):
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 DPM - Pelton Wheel Flow Sensor
A jet of liquid from the flow body's inlet nozzle spins a small flat-blade turbine wheel, and the wheel's rotational speed rises in proportion to the flow rate. Optoelectronics sense the rotation in a non-contacting manner, and the signal is converted into an amplified pulse output or a 4-20 mA analog output.
Seven calibrated water ranges are offered: 0.24–4.8 GPH, 0.8–11.1 GPH, 0.8–15 GPH, 0.8–30 GPH, 0.8–48 GPH, 0.8–60 GPH, and 0.8–80 GPH. Each range has its own model code, from DPM-1153 (brass) or DPM-1553 (316L stainless steel) up to DPM-1195 and DPM-1595.
Versions with the 4-20 mA analog output or compact electronics measure within ±1.5% of full scale. The K000 and F300 frequency output versions measure within ±2.5% of full scale. Staying inside the rated range matters: overrange operation risks bearing damage and major measurement errors.
It measures water and water-based, low-viscosity liquids that are optically transparent, since rotation is detected by an optical sensor through the liquid. A clean medium matters: a filter, for example the KOBOLD MFR magnetic filter, helps keep deposits from building up on the sensor optics.
Two frequency outputs (K000 for OEM use with a 5 ft cable, F300 with an M12 plug), two 4-20 mA analog versions (L343 with Micro-DC plug, L443 with DIN 43650 plug), and two compact electronics packages (C34P with 4-20 mA plus one PNP switch, C30R with two PNP switches).
In the example DPM-1170 N1 K000, the first block sets the flow range and body material (DPM-11.. is nickel-plated brass, DPM-15.. is 316L stainless steel). The fitting code follows: N1 is 1/8" NPT, N2 is 1/4" NPT, G1 is G 1/8, G2 is G 1/4. The final block selects the output electronics.
The compact electronics versions, C34P and C30R, must be ordered with a flow direction. Depending on the model, flow can run vertically in either direction or horizontally in either direction. Orders placed without a required direction are likely to see processing delays, and our technical team can help determine the right specification.
No. The inlet flow is redirected through a nozzle inside the flow body, so no upstream or downstream straight piping is needed. The unit mounts in any orientation as long as the axle stays in the horizontal plane, which makes it a fit for tight installations.
The compact electronics versions carry a built-in 3-digit LED display with user-programmable transmitter span, switch setpoint, and lockout code. For the L443 analog version, the AUF-3000 plug-on indicator adds a 4-digit LED display that draws its power through the 4-20 mA output, with no separate supply needed.
None, as long as the measured medium is clean. If cleaning becomes necessary, the sensor can be opened to reach the internal parts; the blades must not be damaged and the vane has to be repositioned correctly during reassembly. Repairs to the sensor or electronics belong to the supplier, or the guarantee is voided.