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K02 Calibra. Mode

Definition

Sets the correction method for instantaneous flow. Default: Simple Mode, using the formula:

Corrected Instantaneous Flow = K03 × Measured Instantaneous Flow − K04

Parameters K02 (Correction Mode), K03 (Scale Factor), and K04 (Offset Flow) adjust flowmeter reading deviations.

Corrected Instantaneous Flow=K03×Measured Instantaneous FlowK04\text{Corrected Instantaneous Flow} = K_{03} \times \text{Measured Instantaneous Flow} - K_{04}
Calibration Examples (Click to Expand)

1. Error Caused by Liquid Density

Example – 50% Sulfuric Acid Assume the liquid is sulfuric acid with a specific gravity of 1.4. Actual measured weight: 26 tons. The flow meter displays 20,004 L. Converted weight: 20,004 × 1.4 = 28,005.6 kg (≈ 28 tons) → the reading is higher than the actual value.

Step 1: Adjust the K03 scale factor

K03=Actual WeightFlow Meter Displayed WeightK_{03} = \frac{\text{Actual Weight}}{\text{Flow Meter Displayed Weight}} = 26 tons28 tons0.928 \frac{26\ \text{tons}}{28\ \text{tons}} \approx 0.928

Set K03 = 0.928, then the flow meter–calculated weight ≈ 25.98 tons, close to the true value.

Step 2 – Fine adjustment using K04:

  • After adjusting K03, readings may be accurate at high flow, but small deviations can remain at low flow or when the pump starts.

  • Adjust K04 to compensate for fixed offset errors. For example:

  • If readings consistently exceed the true value by 0.1 ton, set K04 = 0.1, and the system will automatically subtract this from the calculated weight.

  • If readings consistently fall short of the true value by 0.1 ton, set K04 = - 0.1, and the system will automatically add this value to the calculated weight.

2. Error Caused by Analog Output

Example The user is using the analog output and finds that the receiving device (e.g., PLC) does not match the value shown on the flow meter.

The meter display shows 0 (no flow in the pipe), but the output current is 4.1 mA instead of the standard 4.0 mA. After conversion at the receiving end, this results in an incorrect flow reading of 0.98 L/min (zero offset).

Step 1: Use Simulation Mode to Check for Scaling Error

If the displayed flow value appears incorrect (for example, a flow reading when no liquid is present), first use Simulation Mode to verify whether a scaling error exists. Refer to the Simulation Mode section for detailed operation.

Enable F02 Simulation Mode, then go to E06 and enable the analog output content (recommended: Flow Rate). Next, enter F01 to set the simulated flow value and observe the reading on the receiving device.

For example, when the simulated value is set to 60 L/min but the receiving end shows 58.41 L/min, this indicates an overall scaling error (reading too low).

After testing with Simulation Mode, it can be confirmed that the issue is not only a zero offset, but also an output scaling error.

Adjust the K03 scale factor

K03=Actual WeightFlow Meter Displayed WeightK_{03} = \frac{\text{Actual Weight}}{\text{Flow Meter Displayed Weight}} = 26 tons28 tons0.928 \frac{26\ \text{tons}}{28\ \text{tons}} \approx 0.928

Set the K03 value to 1.027. After this adjustment, the flowmeter’s converted reading shows a weight of approximately 58.42, approaching the true value of 60.

Step 2: Eliminate the Remaining Fixed Offset (Zero Point Shift)

After adjusting K03, the readings are accurate at high flow rates, but small deviations may still occur at low flow rates or when the pump starts at a fixed flow. To correct this fixed offset error, you can fine-tune the K04 value.

Adjusting K04 to Correct Flow Values

For example, after the user exits simulation mode and the flow returns to zero, if the receiving end still shows a reading of 0.98, set K04 to +0.98. The system will automatically subtract this value from the calculation, effectively zeroing the meter’s reading.

Notes

N/A

Operation Procedure

Button Functions (Click to Expand)

When the main screen is displayed in green backlight, the four buttons function as follows:

  • Blue Button (leftmost): Return, exit, or save settings.

  • Gray Direction Buttons:

    • Left Gray: Previous Page, decrease value, or select item

    • Right Gray: Next Page, increase value, or select item

  • Orange Button (rightmost): Rightmost button: Enter settings, edit, or confirm selection

Button functions may change depending on the operation context to improve usability or prevent accidental presses.

Calibration Offset Function (Click to Expand)

Used to correct flowmeter reading deviations.

Related Parameters: K02: Calibration Scheme, K03: Scale Factor, K04: Offset Flow

1

K02 Calibration Scheme Selection

Currently only Simple Mode is available. No adjustment is required.

2

K03 Scale Factor Setting

3

K04 Flow Offset Setting

4

Calibrate Verification

Verify whether the calibration result meets expectations by checking if the calibrated flow value matches the target value. If not, readjust K03 (Scale Factor) or K04 (Flow Offset) and repeat steps 2–4.

The system automatically calculates the calibrated instantaneous flow using the formula: CorrectedInstantaneousFlow=K03(ScaleFactor)×MeasuredInstantaneousFlowK04(OffsetFlowCorrectedInstantaneousFlow=K03(ScaleFactor)×MeasuredInstantaneousFlow−K04(OffsetFlow

K02 Options, RS485 Values, Read/Write Commands, and Formats

Options
Description
RS-485 Value

Simple mode (Custom)

Currently only Simple Mode is available.

0

Refer to the Read/Write Memory List for the Modbus command format. This parameter uses the Int16 data format.

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