DIGITAL DISPLAY INSTRUMENT 4 20MA RANGE SETTING

That piece of table is correct. The analog output is 4 20 mA, which corresponds to the actual value of 0 14, that is to say, when the output is 4 mA, the corresponding value of the table is 0, and when the output is 20 mA, the corresponding value is 14.

Addendum: Their relationship is proportional, 20 ma corresponds to 14, so how many ma correspond? It should be 20*. Note that it is proportional.

Brother, I see you are using the 4 20 mA percentage measurement function, do you really measure the sensor???

The brother upstairs miscalculated, if you do the way you calculate, it should be milliamps.

You'd better take a look at the manual, the setting of this function of the multimeter of each company is different, and I know that the setting of this function of the Faith multimeter is much simpler than yours.

You can go to ** to find out, this function is generally used for sensors.

You can visit Fishtech ** and have someone to answer for you.

Is the output end of the digital display meter measured with a multimeter? This seems to be a problem, we all use a dedicated one to test together, we haven't tried a multimeter, and there is a loop problem during the test.

Since the milliampere signal is measured, the calculation is very simple, oral calculation: look at the middle value up and down, compare.

If you look at 4-20 like this: if you look at the median value of 12, that is, 14 divided by 2 is 7Analogy.

The calculation formula is: (measured signal-4)*14 (20-4) and whether the circuit is broken during measurement.

The first floor is very right! But both tables are good! Less than 4ma, of course, run the smallest

There must be something wrong with your primary meter! Let's check the table carefully! Please refer to the manual of your quadratic meter for the setting of the quadratic table

You can find the manual and read it carefully, and then ask questions.

Your input is 4-20mA is supposed to be a DC current meter. What does it mean to take turns displaying multiple current values? Your ammeter is a current measured, a current can be displayed if there is a change, do you want to measure the current value of multiple lines?

One is that it can be measured with a clamp ammeter.

The other one may be a three-phase ammeter, with multiple input circuits, I haven't gotten this, and you're still DC, so I don't know.

4-20mA is to provide data for the operation status of the remote PLC or other automatic control systems, such as the pressure transmission Sun Qiliang sensor to the inverter can control the speed, the remote display of the level gauge, etc.

The current signal of 4-20mA is the standard circuit signal prescribed by the International Electrotechnical Organization

The measuring instruments are all using the signal standard of 4-20mA, because any subsequent display instrument can be directly connected, which can be measured from the real instrument. Note that the signal of the display instrument to the input of 4-20mA is not for any range of detecting physical quantities, that is, if the electrical energy range I measure is 0-100kw h, then the display scale of the real meter is set to 0-100kw h, if it is 0-1000kw h, then the range of the real instrument should also be set to 0-1000kw h. That is, the range of the display instrument should be consistent with the range of the detection instrument, so that the detected quantity can be accurately displayed.

If you want to connect to a DCS or PLC in the future, then you can connect directly to the terminal of their analog input module, and any DCS or PLC input module (except thermocouples and RTDs) will accept a current signal of 4-20mA. This means that you can read out the measured value directly on the computer operation screen as long as you set the display range of the module to the same range as the measuring instrument in the DCS or PLC.

The transmitter is connected to the computer through the communication management machine and finally connected to the computer for display, which is used for monitoring.

Hello! Connect the amplifier chip or the AD chip.

As a flow output signal, 4 mA corresponds to 0 flow rate and 20 mA corresponds to the upper limit, so when the current is 4 mA, it is 0 flow.

The lower limit of the range of the flowmeter refers to the minimum flow rate to ensure the accuracy of the flowmeter, not that the flow rate less than the point cannot be measured, but that the error of the measured flow value is greater than the allowable value of the instrument, that is, the accuracy is not considered. In general, as the flow rate decreases, the measurement error increases, and the lower range limit is therefore set.

The signal current of 4-20mA is a standard signal transmitted by instruments and meters that is uniformly used by the International Organization for Standardization.

The starting point of 4mA is used to quickly determine whether the signal loop is open, and once the signal loop is open, the signal current will be zero. Compared with the previous use of 0mA, the starting point can quickly make a judgment, which makes it possible to quickly isolate the false detection signal and eliminate the source of the fault in the detection loop.

The current signal of 4-20mA can be converted into a signal voltage of 1-5V by the standard resistance of 250 EU, when the control loop is composed of a single instrument in the past, the signal voltage of 1-5V can be easily connected in parallel with multiple instruments, such as regulators, alarms, recorders, etc., when one of the instruments fails, it can be isolated and replaced without affecting it. Nowadays, due to the basic use of PLC or DCS as the control system, the signal of 1-5V is relatively small.

The 4-20mA current signal corresponds to the measured value only as a percentage, regardless of the size of the specific measured value. For example, the range of a pressure transmitter is 0-100kpa, then when 0kpa, it is 0 of its full scale, corresponding to 4mA, and when it is 100kpa, it is 100 of its full scale, corresponding to 20mA. The correspondence between them is:

Measured value - zero point value) (range value - zero point value)) current value - 4) (20-4))).

When the current value is known, the measured value can be calculated. Conversely, when the measured value is known, the current value can be calculated. Measurements of temperature, flow rate, level, etc., can be calculated using the same formula, regardless of the size of the measuring range.

If you are a user, then ask the manufacturer If you are a manufacturer, then pretend that you are a customer and ask the manufacturer for technical support.