Archive for the ‘Announcements’ Category

Microlevel now guaranteed for life!

Tuesday, January 12th, 2016
Microlevel by Keller America

Keller Microlevel gets an upgrade!

Keller America has long been known as the only company to offer guaranteed lightning protection, at no additional cost, on many of our level and pressure transmitters. Today, we are pleased to announce that the list of products with guaranteed lightning protection just got a little longer.

The Microlevel is already the smallest diameter media-isolated submersible level transmitter on the market. But now, it includes our lifetime guarantee against damage from electrical surge, which truly makes it the very best value available for groundwater and environmental monitoring applications.

Click here for more information on the Microlevel, or here to view Keller’s other submersible level transmitters.

Keller LevelRat keeps getting better!

Wednesday, October 14th, 2015

2015 has been a big year for the LevelRat. First, it gets an accuracy upgrade effectively doubling its Total Error Band accuracy. Now, the LevelRat comes equipped with dual outputs; one analog and one digital.

The analog outputs you know: 4-20 mA, 0-5 VDC, or 0-10 VDC. These outputs are industry standards and ensure compatibility with most existing infrastructure. But, this is the digital age so digital we shall be. Keller has added RS485 digital communications to the LevelRat opening a whole new world of options and compatibility to arguably the best alternative for wastewater level measurement.

The RS485 output the same Modified-MODBUS communication protocol as Keller’s other digital transmitters. This feature makes direct connection to MODBUS SCADA, PLC, and RTU units possible, allows up to 128 transmitters to be connected on a single bus, and facilitates connection to a PC running Keller’s intuitive CCS30 software which gives users the ability to actively view real-time pressure/temperature changes, run software-assisted level logging, and make adjustments to the analog output to meet your changing requirements.

And yet with all these upgrades, the LevelRat is still built to order in the U.S. in 3 short business days, or less. And the 4-20 mA versions still include Keller’s guaranteed lightning protection. Click here for more information on the LevelRat non-fouling level transmitter.

It is our goal to provide the very best products for your level and pressure measurement needs. We look forward to the opportunity to prove it.


Keller America awarded GSA Contract

Tuesday, August 11th, 2015

We are pleased to announce Keller America has been awarded a GSA Multiple Award Schedule (MAS) Contract. Several products are now listed and available on the GSA Advantage website. Now government and other authorized agencies have direct access to several of Keller’s proven level and pressure measurement instruments.

The complete product list can be found here. Or for more information, contact Keller America here.


GSA Advantage

Virginia Tech Human Powered Submarine Team Successful at ISR13

Wednesday, July 29th, 2015

We, at Keller America, are proud to have been apart of the success of the Virginia Tech Human Powered Submarine team that recently competed in the International Submarine Races in 2015. Keller Pressure Transmitters are used to measure depth and velocity in the VA Tech Submarine

This is the 13th year of competition. This year it was held June 22nd – June 26th, 2015 at the Naval Surface Warfare Center-Carderock Division, Bethesda, Maryland. The ingenuity and creativity of these students is admirable, and they are certain to have a bright future in Engineering.

VA Tech students deply their human powered submarine for ISR13

The ISR began in 1989 with 17 boats entered. It has now grown to include more than 19 teams entering 21 boats from 10 different countries. The competition’s purpose is to inspire a new generation of engineers to participate in the growth and development of maritime science and technology. Per the International Submarine Race’s TM website, the specific goals of the competition are:

“- To inspire students of the various engineering disciplines to delve into broad areas of underwater technology advancement
and to provide them an educational experience that translates their theoretical knowledge into reality.

– To foster advances in subsea vehicle hydrodynamic, propulsion and life support systems.

– To increase public awareness of the challenges people face in working in and exploring the ocean depths.”

Keller, like these students, is committed to the continued growth and development of existing technologies to provide better solutions for the future. It has been our genuine pleasure to support this team and we look forward to their continued success!

LevelRat Non-fouling Level Transmitter Receives Accuracy Upgrade

Monday, May 18th, 2015

Keller LevelRat
Since the Keller LevelRat was introduced, it has challenged the conventional wisdom of wastewater level measurement. The LevelRat has proven that wastewater level transmitters need not be bulky and expensive, that non-stick diaphragms don’t need to be large and fragile, that custom configurations can be achieved without long lead times, and that guaranteed lightning protection is a right, not a privilege.

And, though it may seem impossible to improve on a product of such significance, Keller has done it.  The LevelRat now provides even better accuracy (0.2% FS Static and 0.5% FS Total Error Band), representing double the accuracy under real-world conditions while maintaining the same low price. Isn’t that what you should expect from your level and pressure transmitters? Real value? We think so, too.

For more information on the LevelRat non-fouling submersible level transmitter, click here.

The new

Wednesday, March 25th, 2015

The new Keller America homepage

As you may have noticed, the Keller America website is undergoing significant changes, both in form and function. The new design is built to provide a streamlined experience on IOS and Android mobile devices, as well as your laptop and desktop computers. Special thanks to Dave Berndtson of NetPower Marketing and Will Noel of Data Design Concepts for their help on the new look.

The new site is now live, obviously. But, as with any major change, there may be some growing pains. We apologize for any outages or connection difficulties you may experience as we migrate to the new design. We hope that you enjoy it. Please check back often for more changes to come.


New SDI-12 Level and Pressure Transmitters from Keller

Wednesday, February 25th, 2015

Keller is very happy to announce the addition of the new Acculevel SDI and Preciseline SDI instruments to the Digilevel to offer a complete line of SDI-12 level and pressure transmitters.
Acculevel SDI
The Acculevel SDI is a submersible level transmitter that has a standard 0.1% FS Total Error Band accuracy, but can also be ordered to meet the USGS OSW accuracy specification.

Preciseline SDI
The Preciseline SDI is a pressure transmitter with a 1/4″-18 MNPT pressure connection for use in bubbler applications and offer the same accuracy options as the Acculevel SDI.

These instruments are a lower cost option than the Digilevel and are ideally suited for users that are already familiar with SDI-12 communications,a s they support the SDI-12 v 1.3 commands.

Of course, the Keller Digilevel still remains the flagship SDI-12 transmitter; an excellent instrument for novice and advanced users, alike. The Digilevel communicates via SDI-12 v1.3, or can be placed in one of several modes that emulate other SDI-12 instruments and their unique extended commands. Or, for those users who are less familiar with SDI-12 commands, the Digilevel can be connected to a PC for configuration through Keller’s user-friendly GUI (USB Dongle sold separately).

Click HERE for the Acculevel SDI datasheet.

Click HERE for the Preciseline SDI datasheet.

or Click HERE for the Digilevel datasheet.

OEM Transmitters : All-inclusive

Tuesday, July 8th, 2014

By Daniel Hofer, Dipl.EL.-Ing FH and Bernhard Vetterli, Dipl, Dipl.El.-Ing.HTL

Miniaturization in pressure measurement technology

Keller’s OEM transmitters are systems that can be described as “embedded” in the best sense of the word – and in two different ways. First the sensor and the downstream electronics are embedded in the same housing. And second, the transmitter capsules themselves are ideally suited for embedding in application-specific systems. Depending on requirements, the output signal is standardized and temperature-compensated (ratiometric or digital).

Thanks to Chip-in-Oil (CiO) technology developed at Keller, the trend toward sensor miniaturization is now a reality. This development can offer impressive advantages: an extremely compact structural design, high resistance to electrical noise fields, and high vibration resistance thanks to low mass and short conduction paths.

To put it clearly, CiO technology means that an ASIC is fitted directly next to the pressure sensor – in the same housing – to provide users with a whole range of beneficial functions. However, this does not make the pressure measurement capsule any larger;  Its external dimensions remain the same. This transmitter concept is available in housings 4L…9L, starting from a diameter of 11mm.

Sintered-in pressure-resistant glass lead-throughs feed the transmitter signals outward. The internal Wiring uses short, lightweight bonding wires – with the total exclusion of air in oil. First, this approach eliminates the need to connect filigree signal processing boards with multi-wire cabling in the rest of the installation process for the pressure transducer. And second, there is no need to protect the downstream electronics against moisture and condensation.

Together with the high-grade steel housing, the glass lead –throughs act as feed through capacitors, forming a Faraday cage. This makes the CiO technology extremely resilient to electrical fields. Even field strengths of 250V/m at frequencies of up to 4GHz are unable to influence the measurement signal. The digital interface must be protected by the equipment manufacturer itself.

The ASIC is designed as a microcontroller with the corresponding peripherals, so the sensor signals can be registered with high resolution and dynamism. In addition to the process pressure as such, the temperature of the pressure sensor is measured and is used for mathematical compensation when the signal is processed.

OEM transmitters supply two signals: a ratiometric analog voltage output and a digital inter-integrated circuit interface (12C).

Ratiometric output signal

The secret of the ratiometric format to the output signal is that it actually has no format at all, because it depends on the voltage supplied. This is an inestimable advantage for applications in integrated systems. If the analog-to-digital converter downstream of the transmitter is operated with the same supply voltage, the digital measured value will always be correct. This is because the height if the digitization steps depend on the voltage supply, but the number of steps does not – and their number is the critical factor. Using ratiometric signals substantially reduces the outlay on passing signals from the pressure transmitter to the A/D converter in the downstream electronics, and calibration steps are unnecessary; in the specific case of connection to a microcontroller with an integrated A/D converter, this outlay equals zero. Nevertheless, an interval is specified for the output signal, i.e. 0.5…4.5V for s supply voltage of 5.0V. With a stable and precise supply voltage, this interval can also be used directly as the “standard signal.” The sampling rate of 2 kHz offers amazingly good dynamic scope for a product based on the AD/DA principal. Moreover, the embedded electronics in CiO technology provide constant protection against overvoltage and polarity reversal on all lines up to ±33 VDC.

Embedded interface I2C

OEM transmitters that are the same size as pressure measurement capsules are never connected directly to field bus systems. Instead, the respective coupling modules have corresponding input interfaces, e.g. for the inter-integrated circuit or I2C interface. For years, this has been the serial standard to cope with short distances in embedded systems. The I2C master needs two lines for the serial data and the pulse (clock) for synchronous sampling. Consequently, no timing requirements are specified for the master – which, in fact, determines the timing. Each OEM transmitter has its own address, which is addressed by the I2C master. In the existing configuration, one master could manage 128 different addresses. The pressure and temperature values are registered by means of a request from the master, and are then available at the transmitters (slaves) after less than 10ms, so that they can be clocked out according to a specified protocol. The values are temperature compensated and standardized, and they only need to be scaled from the 15-bit integer to a pressure and/or temperature with units.

Mobile Application

Unlike the CiO version with the ratiometric output, CiO versions with I2C output can operate with a voltage supply of only 1.8…3.6 VDC, so they are excellently prepared for mobile battery-powered applications. In this case, however, features also include the short conversion time of less than 10ms (during which a mere 1.5mA is drawn) and the excellently optimized Sleep mode: unless they are polled, the transmitters remain in this mode, which is typically specified as 0.1µA. If the master allows suitable fast communication, 100 samples per second can be therefore be attained.

OEM transmitters for Everyone

Typical key data vary according to the format of the output signal – ratiometric or digital. With an analog output, the transmitter can be used at temperatures between -40°C and +150°C, whereas the I2C output is subject to an upper limit of 80°C. The pressure range for the analog version extends from 2 bar to 1000 bar; for the digital version, the range is from 2bar to 200 bar. For a greater dynamic scope with increased power consumption up to a maximum of 8mA, the analog version should be chosen. For low voltage and low power applications, the digital version (which also provides temperature information) is recommended.


Keller’s C-series OEM transmitters herald a new chapter in the history of high-integration pressure measurement technology. The Chip-in-Oil concept moves signal processing directly into the protective oil-filled pressure measurement capsule housing, made of stainless steel. Linearization, temperature compensation and parameterization are handles here. For integration into higher-level systems or battery-powered devices, versions are available with ratiometric voltage output or with a serial-digital I2C interface. Various structural designs can be supplied depending on the specific application.

The M5 series – New from Keller

Tuesday, July 1st, 2014

KELLER  is again setting new standards with the M5 series. All in all, the new sensor for static and highly dynamic measurements (up to 50 kHz) represents something totally unique with an operating temperature range up to 180 °C, ±0,1 %FS , miniature size (M5 connection), and the remote signal conditioned 0…10VDC output option.

Ingenious design brings multiple benefits

The key to measuring highly dynamic pressure variance is to achieve the most direct connection possible between sensor element and medium. With this in mind, KELLER has come up with a micro-mechanical solution without media isolation diaphragm, capillary tubing, sealants, or adhesives. In the M5 series, the rear of the silicon sensor is soldered to a supporting element designed for excellent fluid dynamics, which in turn is secured flush at the front of the pressure connection.

This sophisticated design enables dynamic measurements with a bandwidth of 0…50 kHz and offers a number of additional benefits including excellent decoupling of mounting forces and structure-borne vibration, extensive media compatibility, and the durability offered by the anti-oxidation coatings. Other impressive features of the M5 series are its overpressure protection of up to five times the measurement range and its pressure connection with an external thread of just Ø 5 mm for installations in space-limited locations.

Separation of sensor and signal converter

The pressure sensors in the M5 series are intended for operating temperatures between -40 °C and +180 °C with a narrow total error band (i.e. including temperature errors) of ±1%. Without the remote signal converter, they come with a typical output signal range of 80 mV (based on a 1 mA supply) and an individual calibration certificate. The 3 bar, 10 bar and 30 bar measurement ranges are available for absolute pressure measurements. Separating the pressure sensor and the signal converter enables measurements at close proximity, even in units installed in cramped conditions and exposed to high temperatures.

 A top-class signal converter

To avoid any reduction in the piezoresistive pressure sensor’s broad dynamic range of 50 kHz, the KELLER has opted not to digitize the measurement signal to be produced. Instead, the purely analogue signal path is adjusted in real time via the compensation electronics, which are fully controlled by a microprocessor. This ensures the output signal, amplified to 0…10 V, retains the full dynamic range of the sensor signal. The measurement system, consisting of the pressure sensor and signal converter, undergoes an end-to-end calibration at the factory once the customer-specific parameters have been determined. In addition, the operating temperature range of -40 to +125 °C for the remote electronics satisfies the exceptional demands required by engine test benches, for instance.

Series M5 HB

Ideal for measurements at close proximity on engine test benches and in wind tunnels

The thermally ultra-robust pressure transducers in the KELLER M5 series support high-precision static and dynamic measurements up to a bandwidth of 50 kHz and at working temperatures of up to 200 °C at the pressure sensor. With its M5 connection thread, the remote pressure sensor – which contains no oil and associated isolation diaphragm and no sealant or adhesive in contact with the media – is ideal for taking highly dynamic measurements at close proximity. It can even do this at the very thin pipes used in engine test benches, in wind tunnels or during turbine blade tests.

New Keller Video Showcases Pressure Measurement Technology

Thursday, April 3rd, 2014

This newly produced video details Keller’s origins and the products that have made it a world leader in pressure measurement technology.