What is the difference between MASS-VIEW and a VA-meter?
MASS-VIEW® is the digital high-tech alternative to the VA meter or purgemeter. For many industrial processes and chemical plants, Bronkhorst’s MASS-VIEW® eliminates the relative inaccuracy of VA meters, the need to recalibrate for different gases and the safety risk of ruptured glass tubes, at a price directly comparable with the cost of a variable area meter and separate transmitter. For OEMs, it offers the option of incorporating more modern, aesthetic gas flow measuring instruments into their equipment, presenting a more appropriate, high technology image.
The basic advantages of the VA meter are its relatively low cost, reasonable accuracy, simplicity of design, low maintenance and ease of installation. However, one drawback is that flowmeter accuracy degrades when fluid temperatures and pressures fluctuate, whilst there is also a problem of parallax error when taking readings from different viewpoints. In addition, glass and plastic tubes often break in usage, leading to the risk of potentially dangerous gases leaking from the instrument; to compensate, metal tubes and magnetic float sensing are sometimes used instead, but such designs are comparatively expensive, typically double the price.
MASS-VIEW® | VA-meter | |
---|---|---|
Display | Digital OLED display, easy direct or relative reading of actual flow | Visual check on glass could lead to parallax error |
Mounting orientation | Any | Vertical |
Measured flow | Mass flow | Volume flow |
Insensitive for temperature and pressure variations | YES | NO |
Flow path | Aluminum | Glass or plastic |
Output signal | 0-5V and RS-232 and Modbus-RTU | No signal |
Alarms | Standard available with 2 relays | Separate transmitter needed |
Media | Standard 7 gases available | One gas or one liquid |
Accumulated flow rate display | Standard totalizer available in several units readable | Not displayable |
Rangeability | 1:100, 4 pre-installed full scale ranges | 1:10, one full scale range |