DRZ Piston Flowmeter

Brand: KOBOLD Instruments, Inc.

KOBOLD piston flow meters are direct volume counters, also called displacement counter (positive displacement meter). Its function is based on continuous limitation of a definite part-volume of the flow in a measuring cell through continuous filling and emptying of this measuring cell. The measuring cell consists of the measuring chamber and the moving part, the piston.

The piston is driven by the pressure difference between inlet and outlet of the measured media. The revolution is carried forward via a magnet and a magnet field sensor. In cross section the u-formed piston is guided with its piston and guiding-adaptor in a ring chamber at the bottom and top of the measuring-body and also with its slot at the baffle.

The inlet and outlet openings are located on both sides of the chamber's wall.

They are constantly sealed by the piston and the baffle. The incoming measured media fills up the sickle shaped space, it wants to increase this space and therefore turns the piston, until one after the other the volumes V1 and V2 are reached.

While moving ahead, these filled spaces get connected with the outlet nd are emptied. Since both sickle shaped spaces - the inner and the outer - are displaced to one another, the piston movement will not have a dead center. The piston moves continuously depending to the measured flow.



  • ± 1 % of Reading

Ambient Temperature Range

  • -10° to 60° C (14° to 140° F)


  • Consumption Control
  • Dosing & Bottling of Oil
  • Engine-Testing Application
  • Flow Measurement of Mineral-Oil
  • Fuel Consumption Measurement
  • Heating Oil Consumption Measurement

Approvals & Certifications

  • CE

BSP Connection

  • G 1/4" Female
  • G 1/8" Female


  • 3-Digit LED Display
  • 4-Digit Red LED

Electrical Connectors

  • Plug Connection DIN 43650
  • Plug Connector M12×1

Enclosure, Body Material

  • Brass

Environmental Protection

  • IP65


  • 100 μm

Flow Rate

  • 6 to 420 L/hour to Liquid


  • 10 mA
  • 15 mA

Load Impedance

  • 250 ohms - Maximum
  • 500 ohms - Maximum

Materials of Construction

  • Polyoxymethylene - Magnet Holder

Maximum System Pressure

  • psi: 580.2 (kPa: 4,000, bar: 40)

Mounting Position

  • Independent

NPT Connection

  • 1/4" NPT
  • 1/8" NPT

O-Ring Material

  • FPM


  • 0 to 20 mA - Analog Output
  • 4-20 mA - Analog Output

Piston Material

  • Aluminum

Power Requirement

  • 12-28 Vdc
  • 24 Vdc ± 20 %
  • 5-24 Vdc

Process Temperature

  • Maximum


  • ± 0.2 %

Seat / Seal Material

  • FPM

Switch Type

  • NPN


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