Comet Meter Relays

Comet Meter Relays

Panel meters called Meter Relays can also include alarm relays for high and low setpoints. Meter Relays can be connected to building fire alarm panels, interlocked to shut down equipment, or simply turn on warning lights or buzzers.

Panel meters display input signals from sensors measuring voltage, amperage, pressure, flow, and other variables. They are used in control rooms and other places where electrical equipment and sensors are used or remotely mounted at a longer distance for convenient viewing.

For current and voltage Panel Meters, there may be need of a shunt, current or voltage transducer, or current transformer to step down the voltage or current. These sensors are available from TEquipment. Visit Products > Current Sensors

What are Energy Meters?
Energy Panel Meters measure and display the amount of energy consumed by a facility, business, residence, parts of a plant, or individual equipment. The well known electric utility meter is one such energy meter. Panel meters are available for measuring energy too. Besides measuring energy consumption, energy meters can monitor usage, voltages, power factor, and other energy related measurements.

Other Applications for Panel Meters                   
Temperature Panel Meters accept a thermocouple or RTD temperature probe signal to display temperature in °C or °F.

Process Panel Meters accept and display analog signals, such as 0-5 VDC, 0-10 VDC, 4-20 mA, 1-5 VDC, and pulse representing measurements such as pressure, conductivity, flow, temperature, and level.
Counters. Panel Meters can be used to count. Automobile odometers and photocopier copy counters are examples. In manufacturing, it can be used to track equipment use for scheduling preventative maintenance.
Timers. Timers are Panel Meters that count operating time for equipment or count down from a preset time. See the available models from TEquipment at Products > Time/Tach/Strobe Instruments > Stopwatches/Timers/Clocks

Analog vs. Digital Panel Meters
The needle in an Analog Panel Meter is a simple visual, especially when the input signal is varying rapidly. Looking at accuracy, analog panel meters can be equal to digital ones. Digital Panel Meters have better resolution, visibility in poor light, and can be re-configured for different inputs and scaled for input ranges. Analog Panel Meters are dedicated to the input such as Amperage and its range such as 0-10 Amps.

Taut Band vs. Pivot and Jewel Analog Panel Meters

There are two analog panel meter construction types available. Taut-band suspension system eliminates friction and provides strong resistance to shock impact. They are great in a portable instrument. Pivot and jewel is better suited for higher vibration applications. If neither apply to your application, then either will be suitable. Taut Band is more popular.
 
Panel Meter Mounting
 
For a new installation, consider a standard mounting style. It will give independence from the manufacturer should replacement be needed. Replacements of different size panel meters are possible with a panel cutout adaptor plate to fill the void left by the old panel meter.
 
Panels must have a cutout so the meter slides in from the outside. The meter bezel (or lip) will keep the meter from falling through. To keep the meter from falling forward, each manufacturer has a bracketing arrangement to be installed and tightened against the inside of the panel. DIN is a German organization for setting many different standards. For panel meters, DIN sizes have become the de-facto international standard.

DIN Size	Cutout Dimensions
1/2 DIN	184 x 92 mm (7.24 x 3.62 in)
1/4 DIN	92 x 92 mm (3.62 x 3.62 in)
1/8 DIN	92 x 45 mm (3.62 x 1.77 in)
1/16 DIN	45 x 45 mm (1.77 x 1.77 in)
1/32 DIN	22.5 x 45 mm (0.88 x 1.77 in)
	144 x 144 mm (5.67 x 5.67 in). Size made popular by strip chart recorders