Dual piston deadweight testers can greatly enhance a lab?s ability to calibrate wide pressure ranges with the highest accuracy. With transducers and devices under test (DUTs) which have a broad measuring range, calibration can be a lengthy process, as you need to change pistons in between test points to be able to calibrate its entire range.
However, a dual piston deadweight tester is equipped with a high range piston and low range piston, that allows the technician more flexibility and efficiency when it comes to calibration. This advancement originates from decades of innovation and customer interaction to locate a solution for industry needs.
Willpower for pressure calculations
Since the Industrial Revolution, high accuracy pressure measurement is a key requirement in process industries. Pressure measuring instruments like gauges were employed to measure and monitor pressure conditons. They must be calibrated against instruments of an increased degree of accuracy. Deadweight testers (generally known as pressure balances) are high accuracy instruments found in the calibration of electronic or mechanical pressure instruments. The core element of a deadweight tester is a precisely manufactured piston-cylinder system, onto which a mass load is applied so as to generate the average person test points in a calibration.
The mass load is proportional to the mark pressure, which is achieved through optimally graduated masses. The look of the entire calibration system, and also the precise manufacturing of the piston and cylinder, ensure quality performance with long free-rotation time and low sink rates of the piston. With measurement uncertainties down to 0.002% of reading, deadweight testers will be the golden standard in calibration.
A deadweight tester typically consists of a single piston-cylinder system. This involves mass sets to be changed so as to calibrate multiple or wide measuring ranges. Scared may turn into a cumbersome process, one which requires many resources. In 1953, the entity today referred to as DH-Budenberg pioneered the initial dual range piston-cylinder technology with two pistons housed concentrically in one unit. DH-Budenberg was later acquired by WIKA in 2011. The first design included 1/8 in2 (low pressure) and 1/180 in2 (high pressure) pistons housed in one unit. Utilizing a single mass-set it was now possible to generate two points of equilibrium at 55 bar (low pressure) and 550 bar (high pressure) respectively. This is followed with the release of high pressure variant that could generate pressure upto 1100 bar.
Explanation dual piston design
The initial dual piston design was largely constructed of tool roll, and had an accuracy of 0.03 % of the pressure being measured in the typical model and 0.05 % in the ruthless model. In dual piston calibration, the strain on the reduced pressure piston is transferred to the auxiliary piston, that is directly connected to the weight carrier. When correct pressure is obtained, the piston head skirt floats within the reduced range or ?blue band.? To reach high pressure, the pressure is increased and the low pressure piston rises until a knife-edge on the bottom flange makes a seal contrary to the low pressure cylinder and acts as the high pressure cylinder. Because the low pressure piston does not contribute to the overall weight of the piston and weight carrier, the weight carrier picks up the auxiliary weight to pay. When correct pressure is achieved, the piston head skirt floats within the high range or ?red band.?
This iconic, patented DH-Budenberg red and blue band piston-cylinder system was re-engineered later with both piston and cylinder components manufactured from tungsten carbide. With the refinements in pressure generation and piston manufacturing processes, dual ranges are actually available up to 1,400 bar with accuracies down to 0.006 % of reading.
These developments in dual piston technology made deadweight testers, such as DH-Budenberg?s CPB5800 Hydraulic Pressure Balance, the premier deadweight tester for industrial applications. It really is especially useful for calibrating a transducer with a broad measuring range, while maintaining the high accuracy for testing and calibration. With Honored of only a single mass set and calibrating instrument, this system can automatically switch between multiple test points of high and low pressure, making pressure calibration seamless, efficient and economical.
Note
Further information on our pressure balances are available on the WIKA website.