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
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.
KOBOLD pressure sensors series PDD are cost-effective electronic pressure switches with digital indication of actual pressure. Two switch points, on / off-switch delay and hysteresis, are within the measuring range and are programmable.
A piezzo resistive ceramic sensor is used. The units can be used where high switching accuracy is needed. Long-term stability, repeatability and the compact and robust design makes them ideal for use in OEM applicaionts.
KOBOLD pressure transmitter series PDA are cost effective electronic pressure transmitters with digital indication of actual pressure. An analogue output (0)4- 20 mA is available for remote transmission of the measured value. The device is also available with a switch output as well. A piezzo resistive ceramic sensor is used. The units can be used where high switching accuracy is needed. Long term stability, repeatability and the compact and robust design make them ideal for use in OEM applications.
The electronic KOBOLD pressure transmitter and switch PSD with integrated display is used for continuous pressure measurement and monitoring and allows simple switching point programming without pressurisation. For each switching point, the contact function (NC contact/ NO contact), the reset points and the switching function (hysteresis/window function) can be programmed. Switching currents ranging up to 500 mA can be switched by the output transistors. The long-term proven thin-film cells give this pressure switch very good repeating accuracy and a long life, even at high load alternation. The rotating display and rotating electrical connection allow the switch also to be used under extreme mounting conditions. All wetted parts are made of stainless steel, making almost all media restrictions unnecessary for the electronic pressure transmitter/switch. The electronic pressure transmitter/switch PSD can be used for a wide range of measuring tasks in hydraulics and pneumatics.
The vacuum test pump LR-Cal 2941 is used to generate vacuum (negative pressure) for checking, adjusting and calibrating mechanical and electronic pressure measuring instruments by comparative measurements. These vacuum tests may be carried out in laboratories, workshop or on site at the measuring point. If the instrument to be tested and a sufficiently accurate reference measuring instrument are connected up to the test pump, the same vacuum is applied to the two measuring instruments when the vacuum test pump LR-Cal 2941 is is operated. By comparing the two measure valuses at random pressure values, the accuracy can be verified or the instrument under test can be adjusted. Despite its compact dimensions, the vacuum test pump LR-Cal 2941 is easy to operate and allows for exact generation of the required test vacuum. The LR-Cal 2941 is fitted with a fine adjustment valve for precise adjustment of vacuum. Pressure connection is made with 4 mm hose, a T-piece wich quick-coupling and a piece of hose is included in standard delivery.
The pressure test pump LR-Cal LPP 40 is used to generate pressure and vacuum for checking, adjusting and calibrating mechanical and electronic pressure measuring instruments by comparative measurements. These pressure tests may be carried out in laboratories, workshop or on site at the measuring point. If the instrument to be tested and a sufficiently accurate reference measuring instrument are connected up to the test pump, the same pressure is applied to the two measuring instruments when the pressure test pump LR-Cal LPP 40 is operated. By comparing the two measure valuses at random pressure values, the accuracy can be verified or the instrument under test can be adjusted. Despite its compact dimensions, the pressure test pump LR-Cal LPP 40 is easy to operate and allows for exact generation of the required test pressures; a change-over switch enables the generation of vacuum as well. The LR-Cal LPP 40 is fitted with a fine adjustment valve for generation of high pressure and a precise adjustment of pressures. The reference instrument is screwd directly on the top of the pump and the unit under test is connected by means of the connection tube incorporating an adapter 1/4" BSP female thread (freely rotating), contained in the scope of delivery.
The pressure test pump LR-Cal LPP 08 is used to generate pressure and vacuum for checking, adjusting and calibrating mechanical and electronic pressure measuring instruments by comparative measurements in the low-pressure and vacuum range. The pressure tests may be carried out in laboratories, workshops or on-site at the measuring point.
If the instrument to be tested and a sufficiently accurate reference measuring instrument are connected up to the pressure test pump, the same pressure is applied to the two measuring instruments when the pump is operated. By comparing the two measure values at random pressure values, the accuracy can be verified or the unit under test can be adjusted.
The LR-Cal LPP 08 is a pneumatic pressure test pump for low-pressure ranges up to 8 bar with a change-over switch to vacuum down to -850 mbar. Despite its compact dimensions, the pressure test pump is easy to operate and allows for the exact generation of the required test pressures. The maximum pressure or vacuum achievable depends on the attached test volume. The smooth-running pressure generation and the integrated fine adjustment valve allow a safe and precise setting of very small positive resp. negative pressure values in the range of mbar.
The unit under test and the reference instrument can be easily connected with the supplied accessories.
Included in the scope of standard delivery:
The pressure test pump LR-Cal LPP 700 is used to generate pressure for checking, adjusting and calibrating mechanical and electronic pressure measuring instruments by comparative measurements. These pressure tests may be carried out in laboratories, workshop or on site at the measuring point. If the instrument to be tested and a sufficiently accurate reference measuring instrument are connected up to the test pump, the same pressure is applied to the two measuring instruments when the pressure test pump LR-Cal LPP 700 is operated. By comparing the two measure valuses at random pressure values, the accuracy can be verified or the instrument under test can be adjusted. Despite its compact dimensions, the pressure test pump LR-Cal LPP 700 is easy to operate and allows for exact generation of the required test pressures The LR-Cal LPP 700 is fitted with a fine adjustment valve for a precise adjustment of pressures. The reference instrument is screwd directly on the top of the pump and the unit under test is connected by means of the connection tube incorporating an adapter 1/4" BSP female thread (freely rotating), contained in the scope of delivery.
LR-Cal LPP 60-T Description Pressure comparator LR-Cal LPP 60-T in use with reference pressure gauge LR-Cal TLDMM 2.0The pressure test pump LR-Cal LPP 60-T is used to generate pressures and vacuum for checking, adjusting and calibrating mechanical and electronic pressure measuring instruments by comparative measurements. These pressure tests may be carried out in laboratories, workshop or on site at the measuring point. If the instrument under test and a sufficiently accurate reference measuring instrument (e.g. electronic pressure calibrator LR-Cal LPC 300 or LR-Cal LPC 200, accuracy ±0.025% FS) are connected to the LR-Cal LPP 60-T, the same pressure pressure resp. vacuum is applied to the two instruments when the pump is operated. Despite its compact dimensions, the pneumatic pressure comparator LR-Cal LPP 60-T is easy to operate and allows for exact generation of the required test pressures. A change-over switch enables the generation of vacuum as well. The LR-Cal LPP 60-T is fitted with a fine adjustment valve for the precise adjustment of pressures. The reference instrument is screwed directly on to the top of the pump and the unit under test is connected by means of a connection tube incorporating an adapter 1/4" BSP rotating female (optional 1/4" NPT female) port.
Proven primary pressure standard Deadweight Tester / Pressure Balances are the most accurate instrument available on the market for the calibration of electronic or mechanical pressure measuring instruments. The direct measurement of the pressure (p = F / A), as well as the use of high-quality materials enable a very small measurement uncertainty, in conjunction with an excellent long-term stability of 5 years (recommended in accordance with German Calibration Service DAkkS). The deadweight tester / pressure balance has therefore been used for years in factory and calibration laboratories in national institutes, research laboratories and in industry. Stand-alone operation Due to its integrated pressure generation and the pure mechanical measuring principle, the model LR-Cal LDW-P is ideal for on-site use for maintenance and service. Basic principle Pressure is defined as the quotient of force and area. The core component of the model LR-Cal LDW-P is therefore a very pecisely manufatured piston-cylinder-system, which is loaded with masses in order to generate the individual test points. The masses applied are proportional to the target pressure and this is achieved through optimally graduated weights. As standard, these masses are manufactured to the standard gravity (9.80665 m/s²), though the can be manufactured to a specific location (gravity) and also DAkkS-calibrated. Easy operation Depending on the instrument version the pressure is set via an integrated pump or via an external pressure supply by the use of control valves. For fine adjustment a very precisely adjustable spindle pump with a precision spindle running only within the pump body is mounted. As soon as the measuring system reaches equilibrium, there is a balance of forces between the pressure and the mass load applied. The excellent quality of the system ensures that this pressure remains stable over several minutes, so that the pressure value for comparative measurements can be read without any problems, or also so that more complex adjustments can be carried out on the item under test.
The remote data transmission unit ARC1-Tube with logger function is encased in a robust, stainless steel housing, which is ideally suited to installation in 2" monitoring pipes. This unit records measurements made by external sensors (e.g. a level sensor) and periodically transmits the collected data via 2G, 3G, 4G, NB-IoT, LTE-M or LoRaWAN. The high-performance battery and sophisticated power management enable autonomous operation for up to 10 years. KELLER provides a range of licence-free software solutions for configuration and data processing. The easiest and most convenient way to access the collected data is via KOLIBRI Cloud.
The remote data transmission unit ARC1-Box with logger function is encased in a robust, water-tight aluminium housing. This unit records measurements made by external sensors (e.g. a level sensor) and periodically transmits the collected data via 2G, 3G, 4G or LoRaWAN. The high-performance battery and sophisticated power management enable autonomous operation for up to 10 years. KELLER provides a range of licence-free software solutions for configuration and data processing. The easiest and most convenient way to access the collected data is via KOLIBRI Cloud.
The remote data transmission unit ARC1-Box-SB with logger function is equipped with safety barriers and, in combination with intrinsically safe transmitters, it is suitable for use in hazardous applications. The unit is encased in a robust, water-tight aluminium housing. It records measurements made by external sensors (e.g. a level sensor) and periodically transmits the collected data via 2G, 3G, 4G or LoRaWAN. The high-performance battery and sophisticated power management enable autonomous operation for up to 10 years. KELLER provides a range of licence-free software solutions for configuration and data processing. The easiest and most convenient way to access the collected data is via KOLIBRI Cloud.
The remote data transmission unit ADT1-Tube is encased in a robust, stainless steel housing, which is ideally suited to installation in 2" monitoring pipes. The LoRa module, which can be configured on a country-specific basis, establishes a connection with the Internet and makes it possible to collect measurement data in a low-cost and energy-saving manner. These autonomous devices can be linked with digital level sensors and pressure transmitters in the KELLER D and X product lines. With three conventional, high-quality AA batteries, the system can operate autonomously for up to 5 years. The LoRaWAN provider can be selected freely or an in-house or open source infrastructure and associated services can be used. The easiest and most convenient way to access the collected data at the end of the transmission chain is via KOLIBRI Cloud from KELLER.
The remote data transmission unit ADT1-Box is encased in a robust, water-tight plastic housing. The LoRa module, which can be configured on a country-specific basis, establishes a connection with the Internet and makes it possible to collect measurement data in a low-cost and energy-saving manner. These autonomous devices can be linked with digital level sensors and pressure transmitters in the KELLER D and X product lines. With three conventional, high-quality AA batteries, the system can operate autonomously for up to 5 years. The LoRaWAN provider can be selected freely or an in-house or open source infrastructure and associated services can be used. The easiest and most convenient way to access the collected data at the end of the transmission chain is via KOLIBRI Cloud from KELLER.
KOLIBRI Desktop offers all the options for device configuration and displays current measured values and logger recordings in graph form. Thanks to the search and filter options, saved measurement data can be organised with ease and exported as an image, as an Excel or Word report, or in additional formats. All products in the KOLIBRI suite are inter-compatible and can exchange data with one another. The functions are continually being further expanded and optimised.
Proven primary pressure standard Deadweight Tester / Pressure Balances are the most accurate instrument available on the market for the calibration of electronic or mechanical pressure measuring instruments. The direct measurement of the pressure (p = F / A), as well as the use of high-quality materials enable a very small measurement uncertainty, in conjunction with an excellent long-term stability of 5 years (recommended in accordance with German Calibration Service DKD/DAkkS). The deadweight tester / pressure balance has therefore been used for years in factory and calibration laboratories in national institutes, research laboratories and in industry.
Stand-alone operation Due to its integrated pressure generation and the pure mechanical measuring principle, the model LR-Cal CPB5000-HP is ideal for on-site use for maintenance and service.
Basic principle Pressure is defined as the quotient of force and area. The core component of the model LR-Cal CPB5000-HP is therefore a very pecisely manufatured piston-cylinder-system, which is loaded with masses in order to generate the individual test points. The masses applied are proportional to the target pressure and this is achieved through optimally graduated weights. As standard, these masses are manufactured to the standard gravity (9.80665 m/s²), though the can be manufactured to a specific location (gravity) and also DAkkS-calibrated.
Easy operation The setting of the pressure is made via an integrated pump. For fine adjustment, a very precisely controllable spindle pump is fitted, with a spindle running within it. As soon as the measuring system reaches equilibrium, there is a balance of forces between the pressure and the mass load applied. The excellent quality of the system ensures that this pressure remains stable over several minutes, so that the pressure value for comparative measurements can be read without any problems, or also so that more complex adjustments can be carried out on the test item.
Robust instrument design With the high-pressure model LR-Cal CPB5000-HP, calibrations up to a maximum pressure of 5,000 bar are possible. It is built into a stable base and offers exceptional ease-of-use. With the integrated priming pump and the 250 ml tank, large test volumes can also be easily filled and primed.