The analog panel meter has been the indicator of choice for many years. The meter's groundbreaking technology, invented by Sir R. Weston in 1843, allowed a meter to be signal powered. Although it was revolutionary at the time, this same technology presents opportunities for challenges.
For example, the readings from analog meters can be easily misinterpreted. Due to parallax, viewing a meter from different points within a room can result in different readings. Additionally, when the meter reads zero, the operator cannot easily determine if the signal or the meter is dead. Add this to the average ±5% accuracy, and the analog meter seems to be a "for reference only" meter. Users must also consider its sensitivity to shock, vibration and external magnetic fields.
Revolutionizing the measurement and control industry, 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, it facilitated the machine-to-machine interface for onsite automatic process control.
The meters, however, required an external power source. By requiring external power, they came with their own set of complications. If there was not enough power available, it was uneconomical to supply a separate power source. Therefore, it was clear that the digital panel meter needed further advances in its technology to rival the analog meter.
As such, Otek has taken the existing loop-powered technology that has been around for years and revolutionized the way it can be used with the New Technology Meter (NTM), which serves as a 100-percent parasitic signal-powered digital meter.
The NTM allows the control of processes with a Serial I/O connection and detects input failure, conveying a
serially-transmitted distress alarm to supervisory equipment for a minimum of 20 seconds. Likewise, the system is designed to increase safety in the control room and potentially save thousands of dollars.
Otek's NTM units are equipped with trend representation via an automatic tricolor bar-graph/bar-meter (mimicking the modern day traffic light) that has a greatly-increased viewing ability compared to previous models; they also offer the ability for the LED bar-graph to change colors around user-set limits.
Depending on model, the NTM's features also include industrial, military or nuclear grade; a 10-50 mW power requirement; loop, signal or external power availability; 18 different housings to choose from; 1, 2, 3, and 4 available channel models; and analog output, relays, USB, 485, Ethernet, IRDA, and flash memory (µSD).
The NTM, via its auto tricolor bar-graph, 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, opportunities for incidents will be significantly reduced. Further, this intelligent instrument gives users the practical application and cost efficiency of analog meters with the accuracy and reliability of digital meters.
For more information, visit www.otekcorp.com.
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