Winsen FR06 Flow Sensor Instruction Manual

: August 23, 2024
: Winsen

Winsen FR06 Flow Sensor Instruction Manual

Statement

This manual copyright belongs to Zhengzhou Winsen Electronics Technology Co., LTD. Without the written permission, any part of this manual shall not be copied, translated, stored in database or retrieval system, also can’t spread through electronic, copying, record ways.
Thanks for purchasing our product. In order to let customers use it better and reduce the faults caused by misuse, please read the manual carefully and operate it correctly in accordance with the instructions. If users disobey the terms or remove, disassemble, change the components inside of the sensor, we shall not be responsible for the loss.
The specific such as color, appearance, sizes &etc, please in kind prevail.
We are devoting ourselves to products development and technical innovation, so we reserve the right to improve the products without notice. Please confirm it is the valid version before using this manual. At the same time, users’ comments on optimized using way are welcome.
Please keep the manual properly, in order to get help if you have questions during the usage in the future.

Profile

The FR06 flow sensor uses the MEMS thermal principle to monitor the flow of pipeline gas media. This product adopts a low pressure loss design and is widely used in various gas measurements.

Features

High sensitivity；
Very low pickup flow；
High Accuracy；
Low voltage loss;
Modular design;
High measurement repeatability;
Digital IIC or linear analog voltage signal output

Technical Parameters

Structure Parameters

Electrical Index

Our company’s flow sensor adopts 20℃ 101.325kPa and air calibration by default. The production conditions are temperature 22±2℃, purification, (30%~35%) RH environment. If the user has special requirements, calibration will be carried out according to the customer’s requirements.
*·· %FS refers to the full-scale accuracy, and % is the reading accuracy.

Flow Pressure Loss Curve

Interface Definition

The built-in connector model of the sensor is PH2.0-5P. The specific signal definitions are as follows:

Analog Signal Output & Flow Calculation

IIC Communications

IIC connection

This sensor adopts the standard IIC communication protocol, using the serial data bus (SDA) and serial time bus (SCL). The recommended pull-up resistor is 10kΩ.

IIC address

The default address is 0x40, followed by 1 bit of read (1) or write (0) data bit.

IIC communications

Transmission start signal (S) – When the clock line SCL is high, the data line SDA has a falling edge from high to low.
Transmission stop signal (P) – When the clock line SCL is high, the data line SDA has a rising edge from low to high.
Acknowledge (ACK) – SCL sends a positive pulse while SDA is low.
Non-Acknowledge (NACK) – SCL sends a positive pulse while SDA is high.

Command set and data transfer sequence

Communication timing

Traffic collection

Digital flow calculation

CRC check

CRC check uses CRC-8, the initial value is 0x00, and the polynomial is 0x131(x8 + x5 + x4 + 1). The sample code is as follows:

//*****
// Function name：Calc_CRC8
// Function ：CRC8 calculation, initial value: 0x00, polynomial:
0x131(x8 + x5 + x4 + 1)
// Parameter ：unsigned char data：CRC Check array pointer
// unsigned char num：CRC Check data length
// Return ：crc：calculated CRC8 value
unsigned char Calc_CRC8(unsigned char data, unsigned char num)
{
unsigned char bit,byte,crc = 0x00;
for(byte = 0; byte < num; byte++)
{
crc ^= data[byte];
for(bit = 8; bit > 0; –bit)
{
if(crc & 0x80)
crc = (crc << 1)^0x131;
else
crc = (crc << 1);
}
}
return crc;
}

Install and use

Due to the low pressure drop across the sensor, the flow is not fully regulated by the sensor itself. The piping leading to the sensor will also affect the airflow distribution through the sensor, and the measurement results will be affected accordingly. In order to obtain the best measurement performance, it is recommended to configure laminar flow as much as possible. Details as follows:

The gas used must be purified to avoid dust, liquid, and oil. If necessary, a filter device can be installed in the air inlet end of the gas path.
The operating pressure of the medium should not exceed 2 times the maximum operating pressure of the product.
In order to ensure the measurement accuracy of the sensor in the application scenario, it is recommended to install it as follows.

The joints on both sides of the sensor should use G1/8- ∅ 6mm pneumatic joints, and the pipes should be PU pipes with an outer diameter of ∅ 6mm/inner diameter of ∅ 4mm or stainless steel pipes of this specification.

In principle, the requirements of 5.3.1 should be followed when used. If the actual application is different, the manufacturer should be communicated and evaluated.

Fault Diagnosis

Preliminary inspection

Check the opening of air source and inlet.
Ensure the correct connection of communication lines.
Check whether the medium pressure and ambient temperature meet the product technical indicators.