Nitric acid pipeline flowmeterThe causes of the malfunction are as follows: environmental factors; Fluid aspect; Installation aspect.
Environmental reasons: Usually caused by stray current interference in pipelines, strong electromagnetic wave interference in space, and magnetic field interference in large motors. Good separate grounding protection can usually achieve satisfactory results for pipeline stray current interference. However, if strong stray currents are encountered (such as in electrolytic workshop pipelines, sometimes the peak AC potential Vpp induced on the two electrodes can be as high as 1V), additional measures and insulation of flow sensors and pipelines are needed. Space electromagnetic wave interference is generally introduced through signal cables and is usually protected by single-layer or multi-layer shielding.
Fluid related reasons: The presence of uniformly distributed small bubbles in the measured liquid usually does not affect the normal operation of the electromagnetic flowmeter. However, as the bubbles increase, the output signal of the instrument will fluctuate. If the bubbles are large enough to cover the entire electrode surface, they will cause the electrode circuit to break instantly as they flow through the electrode, resulting in greater fluctuations in the output signal. When an electromagnetic flowmeter with low-frequency square wave excitation measures a slurry with excessive solid content, it will also generate slurry noise, causing fluctuations in the output signal. When measuring mixed media, if it enters the flow sensor for measurement before the mixing is uniform, it will also cause fluctuations in the output signal. Improper selection of electrode materials and the measured medium can also affect normal measurements due to chemical reactions or polarization phenomena. Electrode materials should be selected correctly according to the instrument selection or relevant manuals.
Installation reasons: Usually caused by incorrect installation position of electromagnetic flow sensors, such as installing the sensor at the highest point of the pipeline system where gas is prone to accumulate; Or installed on vertical pipes from top to bottom, which may result in emptying; Or there is no back pressure behind the sensor, and the fluid is directly discharged into the atmosphere, forming a non full tube inside the measuring tube.

The functional definition of the terminal block for circular converters is shown in Figure 3-3b

T +	RS485 output+
T-	RS485 output-
P+	Frequency (pulse) output+
PCOM	Frequency (pulse) output ground
DO1	Output of Project 1 #+
DO2	Output of Project 2 #+
ACOM	Project output-
IW+	Passive analog current output+
I+	Active analog current output+/Passive analog current output-
ICOM	Active analog current output-
L1(+)	AC power phase line; DC power supply+
L2(-)	AC power neutral wire; DC power supply-

Nitric acid pipeline flowmeterTroubleshooting method: Resistance method; Current method; Voltage method; Alternative law; Analog signal method; Waveform method.
Resistance method: (1) on-off of flowmeter power fuse and excitation fuse; (2) The connection and disconnection of electromagnetic flowmeter signal cables and excitation cables; (3) The on/off and resistance of the excitation coil of the electromagnetic flowmeter; (4) The insulation resistance of the excitation coil of the electromagnetic flowmeter to ground; (5) Measurement of electrode symmetry; (6) Insulation resistance of electrodes to ground; (7) The resistance value of the flowmeter power transformer.
Current method: measure the output current and excitation current of the flowmeter,
Voltage method: Determine the working power supply,
Alternative method: such as swapping the converter and amplifier board of the flowmeter,
Analog signal method: Use an analog signal generator to provide flow signals for testing flow sensors,
Waveform method: Test key point waveforms based on familiarity with the circuit foundation

Four:Nitric acid pipeline flowmeterApplication industry:
Chemical, environmental protection, textile, metallurgy, mining, medicine, papermaking, water supply, food, sugar production, brewing, irrigation water, sewage treatment.
Five:Nitric acid pipeline flowmeterProduct Technical Parameters
Nitric acid pipeline flowmeterInstrument accuracy: pipeline type 0.3 level, 0.5 level, 1.0 level; Insertion type 2.5 level
Measurement medium: various liquid and liquid-solid two-phase fluids with conductivity greater than 5 μ S/cm.
Nitric acid pipeline flowmeterFlow velocity range: 0.2-12m/s
Work pressure: 0.25MPa~16MPa
Environmental temperature:- 40℃～+50℃
Medium temperature: PTFE lining ≤ 180 ℃
Rubber material lining ≤ 65 ℃
Nitric acid pipeline flowmeterExplosion proof mark: Ex d Ⅱ BT4
External magnetic interference: ≤ 400A/m
Shell protection: integrated type: IP65；
Detached type: Sensor IP68 (5 meters underwater, limited to rubber lining)
Converter IP65
Output signal: 4-20mA DC， Load resistance 0-750 Ω
Communication output: RS485 or CAN bus
Nitric acid pipeline flowmeterElectrical connection: M20 × 1.5 internal thread, φ 10 cable hole
Power supply voltage: 90-220V AC, 24 ± 10% V.DC
Maximum power consumption: ≤ 10VA
Six:Nitric acid pipeline flowmeterTraffic display converter
Display: Display screen: 8-bit LCD with backlight LCD display
Display content: forward accumulation, reverse accumulation, total accumulation
Instantaneous flow rate, flow velocity, air traffic alarm, excitation alarm
Flow rate unit: L/h、L/m、L/s、
Instantaneous flow unit: m3/h、m3/m、m3/s
Accumulated traffic unit: m3、L
Nitric acid pipeline flowmeterLanguage: Chinese or English (other languages can be customized)
Power supply: Voltage range: AC (85-250) VAC or DC (20-24) VDC or battery
Analog output: 0-10mA (load 0-1.5K Ω) 4-20mA (load 0-750K Ω)
Digital frequency output: Output range: 1~5000HZ
Electrical isolation: photoelectric isolation, isolation voltage:> 1000VDC
Output driver: Field effect transistor output, maximum withstand voltage 36VDC, maximum load 250mA
Digital pulse output: output pulse equivalent: 0.001~1.000 m3/cp
Output pulse width: 0.001-1.000 Ltr/cp
Electrical isolation: photoelectric isolation, isolation voltage:> 1000VDC
Output driver: Field effect transistor output, maximum withstand voltage 36VDC, maximum load 250mA
Alarm output: Alarm output points: upper limit alarm, lower limit alarm
Electrical isolation: photoelectric isolation, isolation voltage:> 1000VDC
Nitric acid pipeline flowmeterOutput driver: Darlington transistor output, maximum withstand voltage 36VDC, maximum load 250mA
Communication: Modbus (RS485 or RS232 interface), E-REMOTE（HART）,PROFIBS
Seven:Nitric acid pipeline flowmeterOrdering Information
The quality of the product during use is directly related to the selection of the initial order.
The following parameters are required for ordering and procurement:
1，Nitric acid pipeline flowmeterWhat medium is being measured.
What is the working pressure of the pipeline.
What is the working temperature of the pipeline.
4，Nitric acid pipeline flowmeterThe maximum flow range, normal flow range, and minimum flow range during work.
5. What is the diameter of the pipeline and what material is the pipeline itself made of.
Only if you provide the above parameters can we produceNitric acid pipeline flowmeterEnsure accuracy and stability when using it
Type spectrum

model	caliber
JKM-LDE	15~2600
		code	Electrode material
		K1	316L
		K2	HB
		K3	HC
		K4	titanium
		K5	tantalum
		K6	platinum alloy
		K7	Stainless steel coated with tungsten carbide
			code	Lining material
			C1	Polytetrafluoroethylene F4
			C2	Perfluoroethylene propylene F46
			C3	Polyfluoroethylene FS
			C4	Polyvinyl rubber
			C5	polyurethane rubber
				code	function
				E1	Level 0.3
				E2	Level 0.5
				E3	Level 1
				F1	4-20ADC, load ≤ 750 Ω
				F2	0-3kHz, 5V active, variable pulse width, output high-end effective frequency
				F3	RS485 interface
				T1	Normal temperature type
				T2	High temperature type
				T3	Ultra high temperature type
				P1	1．0MPa
				P2	1．6MPa
				P3	4．0MPa
				P4	16MPa
				D1	220VAC±10％
				D2	24VDC±10％
				J1	Integrated structure
				J2	Split type structure
				J3	Explosion proof integrated structure

JKM-LDE seriesNitric acid pipeline flowmeterReference flow range

Caliber mm	Flow range m3/h	Caliber mm	Flow range m3/h
φ15	0.06~6.36	φ450	57.23～5722.65
φ20	0.11～11.3	φ500	70.65～7065.00
φ25	0.18～17.66	φ600	101.74～10173.6
φ40	0.45～45.22	φ700	138.47～13847.4
φ50	0.71～70.65	φ800	180.86～18086.4
φ65	1.19～119.4	φ900	228.91～22890.6
φ80	1.81～180.86	φ1000	406.94～40694.4
φ100	2.83～282.60	φ1200	553.90～55389.6
φ150	6.36～635.85	φ1600	723.46～72345.6
φ200	11.3～1130.4	φ1800	915.62～91562.4
φ250	17.66～176.25.	φ2000	1130.4～113040.00
φ300	25.43～2543.40	φ2200	1367.78～136778.4
φ350	34.62～3461.85	φ2400	1627.78～162777.6
φ400	45.22～4521.6	φ2600	1910.38～191037.6

Selection of installation environment:
In order to ensure stable operation of the transmitter, the following requirements should be noted when selecting the installation environment:
1. Try to avoid ferromagnetic objects and specific equipment with strong electromagnetic fields (such as large motors, transformers, etc.) to prevent the magnetic field from affecting the working magnetic field and flow information of the sensor.
2. It should be installed in a dry and ventilated place as much as possible, and should not be installed in damp or water prone areas.
3. Avoid direct sunlight and rain as much as possible, and avoid environments with temperatures above 45 ℃ and relative humidity above 95.9%.
4. Choose a place that is easy to maintain and has convenient activities.
5. The flowmeter should be installed at the rear end of the water pump and must not be installed on the suction side; The valve should be installed on the downstream side of the flowmeter.


13、 Installation requirements for straight pipe sections:
Sensors have certain requirements for the upstream and downstream straight pipe sections of the installation point, otherwise it will affect the measurement accuracy.
1. If there is a tapered pipe upstream of the sensor installation point, there should be an equal diameter straight pipe section of not less than 15D upstream of the sensor and an equal diameter straight pipe section of not less than 5D downstream.
2. If there is a gradually expanding pipe upstream of the sensor installation point, there should be an equal diameter straight pipe section of not less than 18D upstream of the sensor, and an equal diameter straight pipe section of not less than 5D downstream.
3. If there is a 90 ° elbow or lower joint upstream of the sensor installation point, there should be an equal diameter straight pipe section of not less than 20D upstream of the sensor, and an equal diameter straight pipe section of not less than 5D downstream.
4. If there are two 90 ° elbows on the same plane upstream of the sensor installation point, there should be an equal diameter straight pipe section of not less than 25D upstream of the sensor and an equal diameter straight pipe section of not less than 5D downstream.
5. If there are two 90 ° elbows on different planes upstream of the sensor installation point, there should be an equal diameter straight pipe section of not less than 40D upstream of the sensor and an equal diameter straight pipe section of not less than 5D downstream.
6. The flow regulating valve or pressure regulating valve should be installed as much as possible outside 5D downstream of the sensor. If it must be installed upstream of the sensor, there should be an equal diameter straight pipe section of not less than 50D upstream and an equal diameter straight pipe section of not less than 5D downstream.
Particular attention
1. If a valve is installed near the upstream of the sensor installation point, constantly opening and closing the valve will greatly affect the service life of the sensor and easily cause permanent damage to the sensor.
2. Sensors should be avoided as much as possible from being installed on very long overhead pipelines. Over time, the sagging of the sensor can easily cause sealing leakage between the sensor and the flange. If installation is necessary, pipeline fastening devices must be installed at 2D positions upstream and downstream of the sensor.
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