Search results

>Why we use 4 ~ 20mA or 3 ~ 15 PSI Standard Signal? 3-15 psi: http://www.allinterview.com/showanswers/181560/why-we-use-3-15-psi-air-for-control-valve-input.html 4-20mA: http://control.com/thread/1274385621#1274385621

A quick look at the McCrometer insertion mag manual shows that its ground electrodes are part of the insertion tube. Being an insertion style, there's no flanged tubes with which to use grounding rings. Is the problem inside the meter or in the transmission of the signal out of the flow...

Yes, AC in, DC out, it's called a DC power supply. There are hundreds of vendors. Google will find them. A 4-20mA sensor' transmitter outputs a signal proportional to whatever it senses. It needs DC voltage to operate. The controller does not 'send' the sensor/transmitter electrical...

1. removal and testing The Crouse-Hinds/MTL app note AN9003 - A Users Guide to Intrinsic Safety discusses removal and testing. http://tinyurl.com/nkd4fwq That section is quoted below: 3.4 Testing of apparatus Sometimes it is suggested that apparatus should be removed for periodic...

> For a vacuum application you need an absolute transmitter. Not always, in fact most vacuum applications are gauge pressure vacuum referencing atmostpheric pressure. A condenser application might well be better served with an absolute pressure measurement reading as opposed to a gauge...

Assuming the RTD is a Pt100, test the transmitter by wiring a 120 ohm resistor, along with whatever jumper(s) needed to simulate whatever the transmitter is configured as, 3 or 4 wire. If the configured LRV is not zero, pick a resistor that will give a reading within the transmitte's configured...

Internally, the TA1 "low" side port is evacuated to a hard vacuum (absolute zero) and sealed. Internally, the TG1 "low" side port is open to the atmosphere, but you can't see it from the outside. The merit issue is for gauge pressure is the relative ease of calibration checks, compared to...

The TG1 is a gauge pressure transmitter. The TA1 is an absolute pressure transmitter. Substituting a TG1 for a TA1 of equivalent range will require ranging the 4-20mA so that the receiver interprets the signal properly. There will be a barometric pressure error because the TG1 references...

I'm lucky, I get to work with round pipes and commercial primary flow elements for liquids and steam. But I notice that the AMCA organization seems to have written the book (the standards) on fan/blower air flow. A call to them might point out the white paper that best addresses your...

1) A water liquid pressure measurement is 'low' by whatever elevation the meter/gauge is mounted above the tap/port. The error varies by the density of the fluid. It's called hydrostatic error. A 28" elevation reduces the reading about 1 psi (water). 0.5m elevation reduces the reading...

Technically, the 4-20mA circuits will overcome the relatively high resistance of T-C wire (0.5 ohm type J, 1.1 ohm type K per running foot) and regulate the current signal over 15m of wire run. But, there is the 'safety' issue in that no one expects a shock level voltage on a clearly...

>"so transmitter will not take account the hydrostatic pressure but the real pressure in the line." On the space station, yes, I would agree, because of near-zero gravity. However, on the planet earth, the acceleration of gravity makes the liquid mass in the pipe weigh something which is...

Here's a couple of liquid vertical flow DP installation diagrams. http://i61.tinypic.com/oac6br.jpg http://i58.tinypic.com/302yxpz.jpg The low side tap is elevated above the high side tap in each, which has to reflect a head pressure difference. A zero flow, with liquid in the pipe...

I stand by my assessment. > Both sides of the element are subjected to the same amount of pressure. The two ports do not see the same head pressure. The pipe is vertical. The DP high side is the tap at the lower elevation, the DP low side is the tap at the upper elevation. The...

For upward flow in a vertical pipe, the total pressure drop is the sum of the pressure loss due to elevation and the pressure drop due to the flowmeter element. If you were to shut off the flow upstream of the orifice plate, with the pipe full of liquid, the reading at zero flow would be 8cm...