The main type of PD meter used for gas flows is the diaphragm meter
. However, diaphragm meters
are being replaced by rotary PD meters for many applications.
Sensus says its patent-pending accuWAVE[TM] diaphragm meter
design will be available on the model 415, Class 400 meter in mid-2010.
To overcome these disadvantages, a diaphragm meter
has been coupled with an MIU (Figure 2), a modified, electronic secondary element of a new generation equipped with a microprocessor.
The major areas of GRI-funded flow research being conducted at the MRF include orifice and turbine meters, ultrasonic flowmeters, gas-sampling methods, and diaphragm meter
The first "dry" gas diaphragm meter
was invented in 1843 by Thomas Glover.
Again, meters were placed in real world measurement applications, in series with a comparison rotary or diaphragm meter
equipped with a corrector and data logger.
British Gas said the following important issues should be addressed with the new meter: (1) The design accuracy of the meter was to be better than the diaphragm meter
; (2) The new meter should be compact; (3) The meter should be easily upgradeable; and, (4) The meter should be part of a modular design so that the metering packaging is aesthetically pleasing.
Trying to come up with a much smaller alternative that is as accurate as the traditional diaphragm meter
but incorporates microprocessor technology is difficult because they tend to be more expensive, so gas utilities are reluctant to utilize them in a big way.
This assessment, through the application of reverse engineering, resulted in developing an estimate of the relative manufacturing cost, reliability, and metering accuracy of each technology normalized to a reference diaphragm meter
, the Rockwell S-275.