Pressure Measurement & Control


Keller sensors for static and ­dynamic pressures

September 2018 Pressure Measurement & Control

Keller’s M5 series, the sensor for static and highly dynamic measurements (up to 50 kHz), represents something unique when considering the operating temperature range (up to 180°C), measurement accuracy (0,1% FS), installation size (M5 connection) and the remote, precise signal conditioning (0-10 V).

Ingenious design brings multiple benefits

The key to measuring highly dynamic pressure variance is to achieve, as far as possible, a direct connection between sensor element and medium. Keller’s development team has come up with a micromechanical solution without media isolation diaphragm (with its damping effect), 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. These include 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 5 mm diameter for installation in space-limited locations.

Separation of sensor and signal converter

The pressure sensors in the M5 series are intended for operating temperatures between -40 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 development team at Keller has opted not to digitise the measurement signal. Instead, the purely analog 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.

Ideal for measurements at close proximity on engine test benches and 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.

For more information contact Instrotech, +27 10 595 1831, [email protected], www.instrotech.co.za



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

VEGA handles the pressures of water treatment systems
VEGA Controls SA Pressure Measurement & Control
A water treatment system for a major metropolitan area in the Midwestern United States demands careful monitoring and management of processes across its sprawling network. Choosing VEGA for its process automation needs meant more than just obtaining precise and reliable pressure sensors.

Read more...
Pressure sensors for hydrogen applications
Instrotech Pressure Measurement & Control
Keller manufactures isolated piezoresistive pressure sensors. The great advantage of the piezoresistive measuring principle is its high stability.

Read more...
Sensor technology for cartonboard machine for paper and packaging
VEGA Controls SA Pressure Measurement & Control
Paper and packaging specialist, LEIPA undertook a comprehensive modernisation project, combining three stock preparation lines into one, and making investments in new plant components and extensive automation technology. Because of the good experiences the company had already had with VEGA sensors, those responsible for planning and maintenance decided in favour of the VEGABAR 82 pressure transmitter as the standard instrument for level and pressure measurement in the new stock preparation system.

Read more...
Pressure measurement without risk of contamination
WIKA Instruments Pressure Measurement & Control
Injectables are among the most sensitive products in the pharmaceutical industry. Sterility is essential during production. For this reason, a manufacturer of biopharmaceuticals decided to implement the pressure monitoring of its processes with hygienic instruments from WIKA.

Read more...
Wind turbines with smart sensors
Instrotech Motion Control & Drives
The wind’s usable kinetic energy increases with the wind speed. Wind turbines, therefore, use kinetic energy to generate torque and then rotational movement. The rotor, consisting of three rotor blades, ...

Read more...
Infrared camera for condition monitoring and early fire detection
Instrotech Temperature Measurement
The Optris PI 640i thermal imager is the smallest measuring VGA infrared camera, with a body-sized volume of 45 x 56 x 90 mm, and weighing only 269 to 340 g, depending on the lens. It counts among the most compact thermal imaging cameras on the market.

Read more...
Pressure monitoring for oil and water tempering machines
Instrotech Pressure Measurement & Control
Temperature plays a significant role in many manufacturing processes. In such cases, a tempering machine is used to maintain the manufacturing process at the desired temperature. Keller supplied PR-21Y piezoresistive pressure transmitters to a client specialising in developing and producing oil and water tempering machines.

Read more...
How to look after your pressure gauge
SA Gauge Editor's Choice Pressure Measurement & Control
Pressure and temperature gauges are very widely used on process plants. Specialising in the design and manufacture of pressure and temperature measuring instruments, SA Gauge believes that all process and ambient factors should be considered when selecting and installing pressure measuring devices. The company recommends that the following guidelines on selection and calibration be followed in order to prevent gauge failure.

Read more...
Process measurement solution for Copper Belt’s Kansanshi Mine
VEGA Controls SA Pressure Measurement & Control
Kansanshi Mine faced measurement challenges in its gland water tanks, slurry, and raw materials in the stockpiles and crusher bins. VEGA was able to offer a suitable solution to resolve these challenges.

Read more...
Temperature monitoring in the metal casting process
Instrotech Temperature Measurement
During metal casting, the liquid material is poured into a mould, and after solidification becomes a solid body. Both too-high and too-low casting temperatures can lead to quality defects. The compact Optris PI 05M infrared thermal imaging camera from Instrotech can monitor the casting process.

Read more...