We will always encounter such and such problems when using pressure transmitters, mainly to tell you about the reasons why the pressure transmitter has no output, for your reference, I hope it will be helpful to everyone's work and study.
If the pressure transmitter is used in conjunction with a digital display meter, at this point, if the digital display table is not displayed, the user may say that the pressure transmitter has no output (which is often encountered by the user). In fact, the problem is obvious, and it is unreasonable to hastily identify a pressure transmitter without output. This is also possible if the pressure transmitter outputs normally and the digital display meter fails. This is the user's misunderstanding and judgment error of the field fault. So how can you tell if the pressure transmitter is outputting properly?Quite simply, use a multimeter to measure the output of the pressure transmitter directly and measure whether a current of 4-20mA is used. Of course, when it is used with other instruments, the situation should first be determined by measuring the current using a multimeter.
We know that the transmitter requires a 24V power supply. If the pressure transmitter has no output, the first thing to consider is whether there is a 24V power supply or whether the 24 power supply is normal. However, if the field is connected in series with a digital display meter or another meter with a 24V power supply (as shown in the dot), the pressure transmitter does not need to provide 24V power again. The second aspect is for pressure transmitters.
If a 24V power supply is available, and the power supply is normal, the pressure transmitter has no output at this time, then check if the power cord is reversed, and whether the positive and negative poles are connected incorrectly.
If the wiring is correct, it is necessary to check the entire circuit for disconnection;Or check if the wrong instrument is selected (the input impedance should be 250), etc.
If all of the above checks are normal, it may be a hardware fault of the pressure transmitter. For example, at the beginning of the field pressure transmitter, due to a 24V power supply problem, the pressure transmitter circuit board burned out, of course, there is no output without a direct display;For example, the overload and pressure resistance of the selected pressure transmitter does not correspond to the site conditions, and there may be excessive pressure, resulting in damage to the pressure transmitter assembly and the pressure transmitter will have no output. For example, pressure transmitters have a field display, i.e. with a gauge. If the head of the table is damaged at this point, the pressure transmitter will have no output. If you judge if the sprinkler head is damaged, both wires directly on the table sprinkler are short-circuited. If the short circuit is normal, the meter head is corrupted.
The above should contain all the common fault causes, the fault factors will of course change with the change of the site, there may be 6, 7 reasons in the future, because at least the above five faults can be said to be basic common sense, including the root cause analysis is very little, these common faults belong to clauses 1 and 5, and are still easy to deal with.