The manufacturer of open channel flowmeter has complete specifications and is automatic and convenient

  Basic introduction of Hehua HHM ultrasonic open channel flowmeter II
Working principle
  The physical quantity directly measured by HHM instrument is liquid level
When it is used for open channel flow measurement, a measuring weir groove shall be installed on the open channel
The measuring weir groove converts the flow in the open channel into the liquid level
The instrument measures the water level in the measuring weir groove, and then calculates the flow according to the water level flow relationship of the corresponding measuring weir groove

Performance characteristics of Hehua HHM ultrasonic open channel flowmeter
5、 Main functions
1
Measure the flow of open channel

  The water level flow look-up table method can be used with any measuring weir groove with a certain water level flow relationship

2
4 ~ 20mA remote current output
The load capacity of 4 ~ 20mA resistance is 500 & omega;
Used for flow meter, 4 ~ 20mA output according to flow; It is used for output of liquid level gauge according to liquid level
4mA corresponds to the zero value of liquid level or flow; The corresponding value of 20mA is set by the key (a parameter)

3
Two SPDT relays
Relay contact capacity is 36V, 1a
It is used for liquid level gauge (E0 = 3
3333), and the two relays make upper and lower limit alarm respectively; It is used for open channel flow meter (E0 = 2
2222)
One relay is used for cumulative flow proportional output, that is, it is closed once every preset cumulative flow (E6 parameter)
Each closing time is 32ms

4
Storage function
The meter can store the data displayed by the meter
The stored data is output by the printer

Not installed & ldquo; Expansion board & rdquo; Only 256 groups of data are stored in the instrument
Each group of data is stored according to the time interval set by the parameter
It can be flow or liquid level

Installation & ldquo; Expansion board & rdquo; Only flow data is stored in the instrument
Record and store by hour, day and month& ldquo; Expansion board & rdquo; There are 255 daily records (including hour records), corresponding to 255 day and hour records
There are 63 monthly records, corresponding to 63 monthly records

5
The printer can be additionally connected to output the stored data (the & mu; p-40tp printer produced by Beigong University)
6
RS232 serial port (three wires: TXD, RXD, GND) is used for networking and remote communication

Technical parameters of Hehua HHM ultrasonic open channel flowmeter
6、 Instrument panel description
1
Power switch: connect / disconnect AC 220V power supply
DC 12V power supply is not controlled

2
Fuse, 0
1A fuse
It is only AC 220V fuse and does not control DC 12V

4
Instrument inner frame fixing gongs and nails
5
Function key prompt: explain the switching method of display and printing mode
6
Keyboard: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 are numeric keys on the keyboard
When setting instrument parameters, a Cyclic shift decimal point; C alternating sign; B cycle movement setting bit; D exit from C6 and C7 status; E
F save the set data

7
Indicator: the indicator is & ldquo; ▲” There are 11 in total
There are four on the display
And & ldquo; on the panel respectively; Instantaneous flow & rdquo& ldquo; L / S & rdquo& ldquo; Liquid level & rdquo& ldquo; Meters & rdquo; corresponding
There are 7 lower displays
And & ldquo; on the panel respectively; Echo & rdquo& ldquo; Wave calibration & rdquo& ldquo; Set & rdquo& ldquo; Run & rdquo& ldquo; Cumulative flow & rdquo& ldquo; M 3 & rdquo & ldquo; Printer & rdquo& ldquo; Print & rdquo; corresponding

Echo & rdquo& ldquo; Wave calibration & rdquo; Respectively indicate whether the probe receives echo or correction wave& ldquo; Run & rdquo& ldquo; Settings & rdquo; It is used to indicate that the instrument is in measurement state or parameter setting state& ldquo; Printer & rdquo; Indicates whether the printer is connected to the instrument& ldquo; Print & rdquo; Indicates that the instrument is outputting data to the printer

8
Upper and lower liquid crystal displays, and the display content is related to the state of instrument keyboard setting

(the following & ldquo; C0 & rdquo; indicates that when the instrument is running, press the C key first, lift it up, and then press the 0 key)
Co: displayed up and down & ldquo_____& rdquo; meaningless

C1: flowmeter status
The upper display is a four digit instantaneous flow value
The unit is L / s
The lower display is the six digit cumulative flow value, and the unit is m3

C2: displays the eight digit cumulative flow, and the lower display displays six digits
The upper two digits appear on the upper display

C3: used under the state of liquid level gauge
The upper display is a four digit liquid level height, in meters
The lower display shows the liquid level alarm
When the water level exceeds the upper limit value, & ldquo-----& rdquo;， When the liquid level is lower than the lower limit, the lower part displays & ldquo-----& rdquo;。 When the liquid level is between the upper and lower limits, it is not displayed on the display

C4: display the continuous working time of the instrument, i
e
excluding the power down time
The time of instrument power failure can be calculated from C4 display
C4 is displayed by the parameter switch & ldquo; 2” Clear to all & ldquo; 0”。 The upper display shows the number of consecutive working days with four digits
The following section is displayed as part of less than one day
There are six digits in total, one group for every two digits
From left to right, they represent hours, minutes and seconds respectively

C5: display calendar clock
There are three groups of six digits on the upper display, one for each two digits
From left to right, they are year, month and day respectively
The lower display has six digits, one group for each two digits, a total of three groups, which are hour, minute and second respectively from left to right
The calendar clock is mainly used to store data and can be calibrated in the setting state

C6 and C7: it is used for displaying memory during instrument maintenance, which is meaningless for using the instrument
If you press C6 or C7 by mistake, press D continuously to return
Or turn off the power, reconnect the power, and then press C1 to enter the operation display
The lower display displays the flow value to be set, in L / s
The corresponding flow value shall be entered with reference to the liquid level value displayed on the display

It is not necessary to set all water level and flow meters
However, there must be a corresponding flow value between the zero water level and the possible maximum water level
For safety, a few more points should be set appropriately above the maximum water level
For example, the distance from the probe to the zero water level is 1m, i
e
L = 1
0000, the water level interval is set to 0
05m, i
e
H = 0
0500, and the maximum water level that may occur in the measuring weir groove is 0
6m
At this time, in addition to h = 0h ~ H = 12h, i
e
the water level is from 0m to 0
6m, except for the flow, in H = 13 * H ~ H = 20 * h, that is, the flow value shall be set on the whole interval from 0
6m to 1m
Between 0
6 ~ 1m, the flow corresponding to the water level at each point can be loaded with the same flow value, for example, the corresponding flow value when h = 20 * H
During the normal operation of the instrument, the meter in this section is not used
The reason why it must be set is to prevent accidental causes
For example, due to rainstorm, the water level exceeds the expected value, or the floating object under the probe, the instrument occasionally has a false high water level, and the instrument will use this water level to check the meter to calculate the flow
If there are several in the table, the short-term flow error will have little impact on the cumulative flow
If the number is not set in the table, it may be the original number of the memory, which may be very large
The maximum possible number is fffff, i
e
16777215 L / s
Such a large flow, even for a short time, will form an error that cannot be ignored in the cumulative flow

Purchase instructions for Hehua HHM ultrasonic open channel flowmeter
Regular return visit: regular return visit to customers by telephone or e-mail to collect user feedback and understand the actual use of products