Compact Pelton Wheel Flow Meter – DTK

The KOBOLD DTK is a compact Pelton wheel flow sensor that measures and monitors low viscosity liquids from 0.8 to 190 GPH of water across eight ranges (0.05 to 12 L/min), with ±2% of full scale accuracy and no inlet or outlet straight piping runs. It offers frequency, 4-20 mA, or compact electronics outputs.

The DTK measures clear or opaque liquids, has a 304 stainless steel housing, and is rated to 430 PSIG with media temperatures up to 284°F (140°C) depending on version. High volume OEM discounts are available.

How the DTK Pelton Wheel Flow Sensor Works

A nozzle built into the inlet fitting directs flow onto an impeller with embedded permanent magnets. As liquid turns the impeller, a Hall effect sensor detects each passing magnet and generates a pulse. The pulse frequency is directly proportional to flow rate, so the signal can be read by external electronics or by an optional display.

The Pelton wheel design provides a repeatable and linear output, and the sensor can be installed in locations where space is at a premium.

DTK Flow Ranges and Measuring Performance

Eight measuring ranges are set by orifice diameter, from 1.0 mm for the lowest flows to 6.0 mm for the highest. Accuracy is ±2% of full scale, with ±1% of full scale linearity and ±0.25% of measured value repeatability. An OEM version with ±5% of full scale accuracy is also offered.

DTK-12U1: 0.8 to 9.5 GPH (0.05 to 0.6 L/min), 1.0 mm orifice
DTK-12U2: 1.6 to 21 GPH (0.1 to 1.3 L/min), 1.5 mm orifice
DTK-12U3: 3.2 to 32 GPH (0.2 to 2.0 L/min), 1.8 mm orifice
DTK-12U4: 5.0 to 55 GPH (0.3 to 3.5 L/min), 2.5 mm orifice
DTK-12U5: 5.0 to 80 GPH (0.3 to 5.0 L/min), 3.0 mm orifice
DTK-12U6: 8.0 to 110 GPH (0.5 to 7.0 L/min), 3.5 mm orifice
DTK-12U7: 8.0 to 160 GPH (0.5 to 10 L/min), 5.0 mm orifice
DTK-12U8: 16 to 190 GPH (1.0 to 12 L/min), 6.0 mm orifice

Each range is also offered calibrated in L/min (DTK-1210 through DTK-1260).

Pressure, Temperature, and Materials

The DTK is rated to a maximum pressure of 430 PSIG (29.6 bar). Media temperature is 5 to 176°F (-15 to 80°C) for standard versions and 5 to 284°F (-15 to 140°C) for the DTK-..0S00 silicone cable version. Ambient temperature is 5 to 140°F (-15 to 60°C). The housing carries IP65 protection.

Housing: 304 stainless steel
Orifice and axle: 316L stainless steel
Rotating vane: PVDF
Gasket: FKM

The standard stainless steel body is designed for use with a wide variety of compatible, water-based liquids.

Output Signal and Electrical Options

The DTK is available with a frequency output, a PNP frequency output with optional pulse divider, a 4-20 mA analog output, or compact electronics with a built-in LED display and switching outputs. Supply voltage ranges from 4 to 24 VDC on the OEM version to 24 VDC ±20% on the analog and compact electronics versions.

Frequency output (DTK-..0P00, 0S00, 0400): 4 to 24 VDC, typically 5 mA, NPN open collector pulse output, max. 20 mA, 5 foot PVC or silicone cable, or DIN 43650 plug connector; supplied without CE mark
Frequency output (DTK-..F300): 12 to 28 VDC, 10 mA, PNP open collector, max. 20 mA, M12x1 plug connector
Frequency output with divider (DTK-..F320, F340, F390): PNP, M12x1 plug connector, divider 1:2, 1:4, or factory set from 1 to 1/128
Analog output (DTK-..L343): 24 VDC ±20%, 4-20 mA, 3-wire, max. load 500 Ω, M12x1 plug connector
Compact electronics (DTK-..C30R, C30M, C34P, C34N): 3-segment LED display, adjustable 4...20 mA analog output (max. 500 Ω), one or two PNP or NPN switching outputs, set via 2 buttons, 24 VDC ±20%, approx. 100 mA, M12x1 plug connector

For the DIN plug version (DTK-..0400), the AUF-4000 plug-on display adds a 4-segment red LED readout and a 4-20 mA, 3-wire output (max. 250 Ω). Mating M12x1 plugs with 6 ft (1.8 m) cable are ordered separately (807.037 for F and L outputs, 807.007 for compact electronics).

Installation and Process Connections

The DTK installs horizontally with ¼" NPT female or G ¼ female threaded connections and needs no inlet or outlet straight piping. Before installation, confirm that the allowable maximum operating pressure and temperature will not be exceeded, and check that the connection between fitting and pipe is tight after mounting.

De-energize the power supply wires before wiring and match the system supply to the instrument's rated supply; incorrect connection will destroy the electronics.

DTK Applications

The DTK was designed for the high volume OEM market and is designed to be an economical choice for measuring low flows. Typical applications include volume dosing and batching with external electronics, laundry machines, PCB manufacturing machines, and agricultural machinery. Optional digital flowrate indicators are available.

Common Questions about DTK - Pelton Wheel Flow Sensor

Liquid passes through a specially shaped flow housing and turns a vane fitted with permanent magnets. A Hall effect sensor produces a voltage pulse every time a magnet passes it, and the frequency of those pulses rises in direct proportion to the flow velocity. The Kobold AUF-4000 plug-on display takes these pulses as its input.

Eight ranges are offered, each defined by orifice diameter: the smallest covers 0.8 to 9.5 GPH through a 1.0 mm orifice, and the largest covers 16 to 190 GPH through a 6.0 mm orifice. Metric calibrated versions span 0.05 to 0.6 L/min up to 1.0 to 12 L/min. Frequency at maximum flow is between 21 and 51 Hz.

Standard versions measure within ±2% of full scale, with linearity of ±1% of full scale and repeatability of ±0.25% of measured value, and the OEM version is rated at ±5% of full scale. The Pelton wheel principle is what gives the DTK its repeatable, linear output.

Maximum operating pressure is 430 PSIG (29.6 bar). Standard versions handle media between 5 and 176°F (-15 and 80°C), while the DTK-..0S00 version with silicone cable extends the media rating to 284°F (140°C). Ambient temperature must stay between 5 and 140°F (-15 and 60°C), and the housing is rated IP65.

The housing is 304 stainless steel, and both the orifice and the axle are 316L stainless steel. The rotating vane is PVDF and the gasket is FKM. The sensor handles clear and opaque liquids alike, and the standard stainless steel construction is intended for compatible, water-based media.

Four families are available: an NPN open collector pulse output on the OEM version, a PNP open collector pulse output on the M12 frequency versions (with 1:2, 1:4, or 1 to 1/128 dividers), a 4-20 mA three-wire analog output for loads up to 500 Ω, and compact electronics combining an adjustable 4...20 mA output with PNP or NPN switching outputs.

The Frequency version accepts 4 to 24 VDC and draws typically 5 mA. The DTK-..F300 runs on 12 to 28 VDC at 10 mA, the DTK-..F390 on 24 VDC ±20% at 15 mA, and the analog DTK-..L343 on 24 VDC ±20%. Compact electronics versions use 24 VDC ±20% three-wire technology and draw approximately 100 mA.

The Pelton wheel design eliminates the need for straight piping before or after the sensor. The specified installation position is horizontal, and the sensor has female threads in ¼" NPT or G ¼. After mounting, verify that the fitting-to-pipe joint is tight before putting the unit into operation.

Overflows of more than 20% might damage the bearings and cause larger measuring errors or malfunction, and any use beyond the manufacturer's specification may invalidate the warranty. Pressure loss at maximum flow is 13.1 to 15.6 PSI (0.9 to 1.1 bar) depending on orifice diameter.

Yes, two options exist. Compact electronics versions (DTK-..C30R, C30M, C34P, C34N) mount a 3-segment LED display on the sensor, with settings made through two buttons. For the DIN plug version, the AUF-4000 plug-on display provides a 4-segment red LED readout, operates from -4 to 176°F (-20 to 80°C), and can only be calibrated with a factory-mounted sensor.