The turbine flowmeter model DOT consists of a helically shaped turbine rotor supported in two tungsten carbide bearings, the rotor being solid ferritic stainless steel of a grade compatible with the metered liquid, all contained within a housing of non-magnetic stainless steel. A pick off coil having a permanent magnet core is mounted in the housing adjacent to the rotor blade tips such that a magnetic circuit is set up via the rotor blades. Rotation of the rotor varies the reluctance of this magnetic circuit and the flux changes induce a small voltage in the coil, the frequency of which is directly proportional to the rotor speed and therefore proportional to the volumetric flow rate. The effects of increasing viscosity reduce the linear flow range and shifts the k-factor. Further, the effect of viscosity depends on the frequency (RPM of rotors). Therefore, smaller the meter, higher is the effect of viscosity on the linearity curve.
The Kobold Differential Pressure Transmitter model PAD is a micro processor-based high performance transmitter, which has flexible pressure calibration and output, automatic compensation of ambient temperature and process variable, configuration of various parameters, communication with HART ® protocol. The application is very various, as measuring pressure, flow and level by application method. All data of sensor is to be input, modified and stored in EEPROM. As an option the Kobold Pressure Transmitter is also available as a flow meter. This flowmeter model PAD-F has added the totalizing function in the PAD transmitter. So it is available to check the flow rate and totalizing flow. It measures the flow rate by using differential pressure without compensation of temperature and static pressure. The shape of the PAD-F is the same as the standard device and it is only the terminal block which is different since there are two more terminals for the read-out of the pulse output.
The KOBOLD Pressure Transmitter model PAS is a micro processor-based high performance transmitter, which has a flexible pressure calibration and a flexible output signal. It has an automatic compensation of ambient temperature and process variables. A communication with the instrument and a configuration of various parameters is possible via the HART ® protocol. All data of sensor is to be input, modified and stored in an EEPROM.
The new KOBOLD type DUK flow meters are used for the measurement, monitoring, metering and dosing of low viscosity fluids. The devices work on the principle of the difference in running times. This is based on the fact that ultrasonic waves in a medium are influenced by the speed of flow. Two sensors mounted opposite one another in the pipeline function simultaneously as transmitter and receiver of ultrasound signals. If there is no flow, then the running times of both signals are identical. If the medium is flowing, then the running time of the signal against the flow is longer than that with the flow. The running time difference, which is determined by a microprocessor, is proportional to the speed of flow. The devices can be equipped with a switching output, a frequency output or an analogue output. In addition, a compact circuit can be selected that features a digital display, a switching output and an analogue output. The device series is rounded off by an optionally available dosing and meter circuit. The meter circuit indicates the momentary flow rate in the first line of the display and the partial or total quantity in the second line. A dosing circuit controls simple filling tasks and similarly measures flow rates, total amounts and filling amounts. The analogue output and two relay outputs can be used for further processing of the signals
NGM uses TDR (Time Domain Reflectometry) technology, which is also known as Guide Microwave or Guided Wave Radar. This means that low-energy and high-frequency electromagnetic impulses, generated by the sensor’s circuitry, are propagated along the probe which is immersed in the liquid or solid to be measured. When these impulses hit the surface of the media, part of the impulse energy is reflected back up the probe to the circuitry which then calculates the level from the time difference between the impulses sent and the impulses reflected. The sensor can output the analysed level as 4 ... 20 mA analogue output, or it can convert the values into freely programmable switching output signal.
The KOBOLD flow meter models DPL are used to measure and monitor liquids. It's compact design allows it to be used in equipment where space is at a premium. The large number of pulse evaluation options offered means that the system is suited for a wide range of applications.
KOBOLD rotating vane flow meters series DRG are used for measuring and monitoring low viscous liquid. Series DRG flow meters are working according to the well-known rotating vane principle. A magnet fitted in the can and hermetically sealed from the medium transfers the non-contacting rotary motion to a Hall-effect sensor mounted in the housing. The sensor converts the rotary motion proportional to the flow to a frequency signal. A series connected electronics unit converts the signal to an analogue output, limit contacts or display.
An electrically conductive medium induces a voltage while flowing through an arranged magnetic field in accordance to the Faraday's induction law. The electrode currency is proportional to the flow velocity and therewith to the volume flow. The PIT-Sensor is available with integral or remote mount transmitter. A retracting device for mounting and dismounting under process conditions is available. The magnetic-inductive PIT flow velocity sensor is used to measure or monitor the volume flow of liquids, slurries, pastes and other electrically conductive media while minimizing pressure drop. Pressure, temperature, density and viscosity do not affect the volume measurements. Portions of solid particles and small gas pockets should be avoided.
The KOBOLD Gear Wheel Flowmeter series DZR have been designed for a flow measurement for viscous liquids. The measuring unit consists of a pair of gear wheels which is moved by the flow according to the principle of gear wheel motor. The bearings are – according to the material combination – either ball bearings or gliding bearings. The movement of the gears is sampled without contact by means of two sensors located in the cover. Between sensor compartment and measuring chamber is located a pressure-resistant, non-magnetic separator plate. The different versions vary through housing materials, bearing assembly, through the medium being used and the accuracy. The mounting position and flow direction is arbitrary.
The Kobold gear wheel flow meter model KZA for viscous liquids is a low-cost flow meter. The movement system consists of a gear set propelled by the flow. The instrument movement bearing is designed for the types KZA-1810 and KZA-1865 as radial and axial gliding bearings. The type KZA-1816 has a ball bearing.
The pick-up is separated from the measuring chamber and registrates the gear resolution contactlessly through the housing wall.
Easy maintenance, slight pressure loss, small weight and low noise level are the outstanding features of this flow meter.
Applications
The Series PD-39 X does not measure the differential pressure directly – instead, it uses two absolute pressure sensors to take the measurement indirectly. As well as reducing costs, this differential pressure transmitter is also more robust in relation to unbalanced (one-sided) overloading. The differential pressure range should be at least 5% of the standard pressure range. Each pressure side has two pressure connections, so the Pressure measurements can be displayed and recorded on PC or Laptop with help of the software ControlCenterSeries30 (CCS30) and a seriel interface cable. Export of recordings to usual file formats possible. Up to 128 devices can be connected together into a KELLER Bus-system. The Series PD-39 X does not measure the differential pressure directly - instead, it uses two absolute pressure sensors to take the measurement indirectly. As well as reducing costs, this differential pressure transmitter is also more robust in relation to unbalanced (one-sided) overloading. The differential pressure range should be at least 5% of the standard pressure range. Each pressure side has two pressure connections, so the PD-39 X is easy to use in pressure lines So that the differential pressure can also be measured exactly if the standard pressure range/ differential pressure ratio is high, this series also features the tried-and-tested microprocessorbased technology that is used in Series 30 X. All reproducible pressure sensor errors (i.e. nonlinearities and temperature dependencies) are entirely eliminated thanks to mathematical error compensation. The sensor signals are measured with a 16-bit A/D converter, so the individual standard pressure ranges can be measured to an accuracy of 0,05%FS throughout the entire pressure and temperature range. Digital Interface The transmitters have a bus-compatible two-wire RS485 half-duplex interface which is modelled on the ”MODBUS RTU”. KELLER offers interface converters to RS232 or USB for use here. The READ30/PROG30 program and the protocol are freely available. The interface offers these capabilities: - Readout of pressure and temperature values for both sensors. This allows readout of the diffe- rential pressure as well as the two standard pressure ranges. - Calibration of zero points and amplification. - Scaling of the analog output to different pressure ranges or units. - Configuration settings such as measurement rate, low-pass (LP) filter, bus address, etc. - Readout of information such as serial number, compensated pressure and temperature ranges, etc. Analog Output The analog output is freely scalable via the interface. For flow measurements, the root of the differential pressure can also be outputted. The calculated value can be outputted via an analog interface (0…10 V or 4…20 mA).
The Series 41 X combines the ceramic measurement cell for low pressure ranges with the µP electronics of the digital Series 30 transmitter. The pressure values from the signals of the pressure and temperature sensors are determined by polynomial compensation (see reverse). The values can be displayed and stored on a PC via an RS485 interface and programming can also be carried out. The transmitters are calibrated to the base range. The PROG30 software permits programming of the analog output signal in each section of the range within the base range (e.g. range 100 mbar. Output 4…20 mA for 20…60 mbar). With KELLER RS converters K-100 Series, up to 128 transmitters can be hooked together into a bus system and read by means of a PC or laptop. READ30 software allows the current pressure of each transmitter to be read or the pressure activity of several transmitters to be recorded or stored whilst “on line”.
Piezoresistive pressure transmitter for applications in bio-reactors or autoclaves. The transmitter is compensated up to 150 °C and may be operated continuously or sterilised at this level, including the special circuit electronics The transmitters are supplied in absolute or gauge versions, with current or voltage output. The sensing component is a micro-machined silicon pressure chip of high sensitivity. An independent temperature sensor is integrated on the surface of the silicon chip
Series 22 DT was developed and homologated specially for use in so-called "bivalent" vehicles fitted with engines for combined natural gas/gasoline operation. The unconventional design with a small mass swept by the flow results in a fast response with temperature changes, the temperature being measured by an NTC or PT sensor located directly behind the stainless steel separating diaphragm. The same diaphragm transmits pressure via a capillary to a stress-free mounted silicon measuring cell. The signal processing for pressure and temperature is carried out by an electronic module connected to the sensors by flexible conductors. Mounted to the back of the electronic module, which is directly connected to the 6-pole plug connector are the EMC protection components. A special feature is the immunity from interference from electromagnetic fields up to 200 V/m.
Series 22 offers a reliable cost effective solution for customers requiring medium to high quantities, of mass produced transmitters. Utilising the KELLER automatic brazing lines, this new technology allows crevice-free construction of the pressure port with no internal seals or O-rings, making possible high volumes at low cost. In the brass 22 M, a steel insert and a nickel diaphragm are brazed into a brass housing. In the steel 22 S, all parts are stainless steel (AISI 316 L). The glass feed-through header and silicon pressure sensor are welded to the steel insert underneath the oil filling. The electronic circuit is fitted to the Packard plug. EMC-protection-components are mounted on the plug side, the amplifier on the sensor side. A flexible printed circuit “TAB” connects the sensor with the electronics. The transmitters are designed to have exceptionally good EMC ratings and operate over a wide temperature band, ideal for automotive, hydraulic and refrigeration control applications
The DCX-18 ECO is an autonomous, rechargeable battery powered instrument. It features a stainless steel 18 mm in diameter housing designed to record pressure (water depth) and temperature over long periods at a very economical price. Its small size, rechargeable battery, fully welded housing and the relative sensor option are just a few of the many advantages provided by the DCX-18 ECO. The electronics employ the latest microprocessor technology which give high accuracy and resolution for the pressure and temperature signals. The measured values are mathematically compensated for all linearity and temperature errors of the pressure sensor. The use of a non-volatile memory for data storage ensures high data security. DCX-18 ECO The sensor, electronics and the rechargeable battery are housed in a fully welded stainless steel tube for submersible deployment. For data read-out, the DCX-18 ECO must be recovered from the measurement point. The end cap, sealed by two O-Rings, must then be removed to access the serial interface. The DCX-18 ECO works with an absolute pressure sensor. In shallow water depths where the influence of barometric pressure changes should be considered, it is recommended that a second data logger (Baro) is placed at the surface, to record the barometric pressure. The PC then calculates the differential pressure resp. the water depth by subtracting the two measured values. DCX-18 ECO with cable (DCX-18 ECO SG or DCX-18 ECO VG) An optional cable is available for the DCX-18 ECO, enabling data retrieval or configuration and charging the battery without removing the data logger. For relative measuring devices, the cable incorporates a capillary tube which enables venting the relative sensor. Rechargeable Battery: The DCX-18 ECO is charged over the USB connection with the K-104M converter connected to PC. For fast charging, connect the power supply unit or the car charging adapter to the converter. The charge status is displayed in the logger software
The DCX-22 is an autonomous, battery powered instrument made of stainless steel designed to record water depth (pressure) and temperature over long periods. Two versions are offered: DCX-22 The sensor, electronics and battery are housed in a sealed stainless steel tube, for submersible deployment. For data read-out the DCX-22 must be recovered from the measurement point. The O-ring sealed end cap is then removed to access the data port. The DCX-22 works with an absolute pressure sensor. In shallow water depths where the influence of barometric pressure changes should be considered, it is recommended that a second data collector DCX-22 (Baro) is placed at the surface, to record the barometric pressure. The PC then calculates the differential pressure resp. the water depth by subtracting the two measured values
The DCX-25 PVDF is an autonomous, battery powered instrument designed to record water depth (pressure) and temperature over long periods. The housing is made of polyvinylidene fluoride and the sensing diaphragm is available in either Hastelloy C-276 or titanium 6AL-4V. This combination of wetted materials ensures compatibility with even the most aggressive media This data collector (Ø 25 mm) integrates a pressure sensor, electronics and battery in one housing. The electronics employ the latest microprocessor technology, which give high accuracy and resolution for the pressure and temperature signals. The built-in pressure sensor is mathematically compensated for all linearity and temperature errors. The use of a non-volatile memory ensures high data security. The DCX-25 PVDF works with an absolute pressure sensor. For installation, the data collector is secured by a suspension cable and immersed into the media to be measured and must be recovered for data readout. In shallow water, where the influence of barometric pressure changes should be considered, it is recommended that a second data logger (e.g. DCX-22 Baro) is placed at the surface to record the barometric pressure. The Logger PC software then calculates the water depth by subtracting the two measured values. The housing of the data logger can be opened easily without any tools, thus allowing quick access to the replaceable battery and the interface connector for configuration and data download. Interface with a PC is accomplished using one of Keller’s converter cables which are available in either RS232 connection (K103A) or USB connection (K104A). The necessary converter drivers are included with converter purchase, along with the Keller Logger software. This intuitive software provides the capability to customize the instrument, as needed, for each installation. Users can configure the DCX-25 PVDF to record at fixed time intervals, using fixed or eventbased start times, in user-selectable measurement methods to ensure that only the most useful and meaningful data is collected and stored. For applications that do not require highest compatibility with aggressive media, Keller offers the DCX-16, DCX-18, DCX-22 and the DCX-38.
The DCX-38 VG is an autonomous instrument for recording water level with a high resolution and full scale ranges as low as 0,5 mWC / 50 mbar. It features a rugged, gold-plated ceramic diaphragm for outstanding long-term stability and stainless steel housing with user serviceable battery for long service life. Configuration / Data Retrieval: For data readout, the serial interface is accessed via the data port located on one end of the cable, enabling on site data retrieval. Using either the K-104A or K-103A converter cable, the DCX-38 VG connects easily to a laptop or PC via USB or serial port. Used in conjunction with Logger 4.X software, the DCX-38 VG is configured and data retrieved either in the lab or the field
LEO 2 is a compact, micro-processor (µP) controlled, highly accurate and versatile pressure measuring instrument with digital indication. The piezoresistive pressure transducer as the heart of the instrument has gone through extensive pressure- and temperature tests. Its characteristics are stored in the instruments internal EEPROM. The µP of the LEO 2 reads the characteristic values and calculates therefrom the pressure to an accuracy of < 0,1 %FS at room temperature. The pressure is measured twice per second and displayed. The top display indicates the actual pressure, the bottom display shows the Max.- or Min.- pressure since the last RESET. Also available as intrinsically safe version (LEO 2 Ei).
The LEO 5 combines the notable features of Keller’s successful LEO-Record and LEX 1 digital pressure gauges, featuring an IP66-rated stainless steel enclosure. This robust housing combines contemporary microcontroller-based electronics and capacitive-touch controls, operated through the environmentally-sealed safety glass front panel. The large backlit LCD display ensures readability in any lighting conditions. Two selectable measurement modes, standard and peak, are included to ensure maximum versatility. In standard mode, high-resolution pressure measurements are taken twice per second. When operating in peak mode, sampling frequency increases to 5 kHz with 16 bit resolution. The LEO 5 interfaces with a PC via USB connectivity, allowing access to active measurements and recorded data including pressure, peak pressure, temperature, and measurement interval. PC connection also allows device configuration, firmware updates, and recharging of the integral accumulator power supply. The unique modular design of the LEO 5 makes possible adaptation to customer-specific measuring requirements.
LEO 5 CA offers a user-friendly way to represent the pressure measurement at the bottom of a tank as the quantity of remaining liquid. At the push of a button, the microcontroller performs the calculations using the information of the tank shape and dimensions and displays the remaining tank content quantity on the clearly legible 5-digit LED display in the desired unit (litres, gallons etc.). The unit is configured using a PC and the easy-to-use software so that the filling level, which determines the pressure, can be converted into an appropriate filling quantity. First the tank shape is selected, then the tank dimensions and the specific gravity of the liquid are entered. It contains the most current tank shapes. The program covers the most common tank shapes, but also enables any shape by entering the parameters into a specified table. The exclusive use of absolute pressure sensors in the LEO 5 CA system eliminates the use of capillary vented cables with all the problems associated with a gauge pressure measurement. The LEO 5 CA housing integrates an air pressure sensor, ranged between 0,8 bar and 1,2 bar absolute. The sensors to measure the hydrostatic pressure at the bottom of the tank are calibrated from 0,8 to 1,8 bar abs for tanks up to 5 m in height, and 0,8 to 2,3 bar abs for tanks up to 10 m in height. The pressure difference, calculated by the micro-controller, is the relative hydrostatic pressure. The content of a pressurised tank is determined using the difference between the measurements from two absolute pressure sensors located at the top and bottom of the tank An accuracy of the system of up to 2 mbar (corresponding to a 2 cm water column) is achieved using a computerised calibration and compensation procedure for the pressure sensors. LEO 5 CA makes it possible to connect various pressure probe transmitter versions (with thread, front-flush with flange, or submersible sensors). The power supply to the system (8 to 28 V) can be provided externally or internally from an accumulator or a battery. The display is obtained by pressing the button on the front, and the value appears for a configurable duration. The LEO 5 CA has two switch outputs with configurable functionality and threshold values. The device must be supplied externally if the switch outputs are used.
The pressure transducers of the PD-10L series have been developed to measure differential pressure. These OEM pressure transducers have a single silicon diaphragm in their interior, which is pressurised from both sides and measures the pressure difference directly. This design enables them to measure tiny pressure differences even at an extremely high line pressure.
The low-cost OEM pressure transducers of the 6S series are based on a piezoresistive measuring cell with a brazed metal diaphragm in a steel housing.