Advancements in Digital Meters Replace Analog Meters
While the analog panel meter, invented by Sir R. Weston in 1843, has long been the indicator of choice, and was groundbreaking at the time of its invention, its signal power capabilities present opportunities for accidents because it can easily be misread.
Due to parallax, viewing a meter from different points within a room can result in different readings. Also, when the meter reads zero, the operator cannot easily determine if it is from the signal reading or a result of the meter being dead. Add to this, an average of +5% accuracy. Additionally, with analog metes, one must consider its sensitivity to shock, vibration and external magnetic fields.
Then the measurement and control industry was revolutionized and the digital panel meter became available. Digital meters changed the consumer market by offering numerical display with illuminating interpretation and a low percentage (+) accuracy discrepancy. In addition, the meter facilitated the machine-to-machine interface for onsite Automatic Process Control.
While digital meters have showed tremendous progress since analog meters, one important factor must not be ignored. Digital meters require an external power source. By requiring external power brings with it an entirey new set of problems.
When power is not available, it is uneconomical to supply a separate power source. So it soon became clear as it had with the analog meter, that the digital panel meter needed further advancements in its.
Replacing control room meters has been inevitable for so many companies, but also somewhat of a chore.
For years, control personnel questioned what would be the best replacement for their control rooms. If the analog meter was chosen, it would provide little accuracy, but require a low replacement cost with no rewiring? If the digital meter was chosen, it would offer more accurate readings, yet require a high replacement cost and rewiring?
Today, Otek's New Technology Meter (NTM) rivals both older models of the analog and digital meters with their parasitic signal-powered digital meter.
Depending on model, the NTM’s features can include:
- Industrial, Military or Nuclear grade.
- Available in loop, signal or external powered.
- Requires only 10-50mW power.
- 18 different housings to choose from.
- 1, 2, 3 and 4 channel models available.
- Automatic tricolor bargraph (mimicking the modern day traffic light).
- Loop/Signal failure detection with serially transmitted distress alarm to supervisory equipment.
- Analog output, relays, USB, 485, Ethernet, IRDA and flash memory (µSD).
The NTM, via its auto tricolor bargraph, brings the trend of the needle indicator, along with digital accuracy and introduces dead signal notification and alarming. With this new addition to the process measurement and control industry, accidents should be reduced. This new instrument delivers the practical with cost efficiency accuracy alongside.