Working principle and operation method of FYP-1 digital precision barometer:

1. Working principle

FYP-1 Precision Digital BarometerUsing an intelligent silicon piezoresistive pressure sensor, the silicon piezoresistive sensing element converts changes in air pressure into changes in the output voltage of the bridge, which is amplified inside the sensorA/DTransform and output in digital form. The pressure sensor also has a temperature sensor inside, and the temperature signal is output in digital form for temperature compensation of the pressure sensing element.

The calibration parameters stored in the sensor and the measured pressure and temperature digital signals are read into the microcontroller using a serial method using a microcontroller. The microcontroller then performs nonlinear calibration calculations, temperature compensation calculations, zero position correction calculations, etc. to obtain the air pressure value, which is displayed on the monitor.

For the convenience of different users, this instrument can display air pressure in three units:hPaTheMmHgTheinHg,The conversion relationship between them is as follows:

1 hPa(hectopascals)= 0.75006 mmHg(millimeters of mercury)

1 hPa(hectopascals)= 0.02953 inHg(inches of mercury)

There is a power supply voltage monitoring function inside the instrument. When the power supply voltage is lower than3.3VWhen the screen appears”LLLL”The prompt identification,Prompt the user to replace the battery.

2. Operation process：

Before use, three batteries need to be inserted into the battery compartment of the instrument 5number1.5VWhen installing dry batteries, please pay attention to the polarity of the battery and follow the polarity marked in the battery box. Please do not install the battery polarity in reverse. If using an AC power source, please provide the randomly attached5VConnect the input terminal of the stabilized DC power supply220VThe mains power is connected to the external power interface of the instrument at the output end.

After installing the battery, the instrument may be turned on or off. At this point, the "Power Switch" button on the panel can be used to switch between power on and off states.

After turning on, the LCD monitor briefly displays all strokes to check if each section of the LCD monitor is intact. After the display is completed, the instrument automatically enters the measurement state. Pay attention to the signs of low battery level”LLLL”Does it appear? If there is a sign of low battery, please replace the battery in a timely manner (power testing is only performed every time the device is turned on). What is the unit of data displayed on the instrument when it enters the measurement state after booting uphPa,If you want to use other units for display, you can use the "Unit Switch" button to switch.

When continuously pressing the 'Unit Switch' button, the units of the displayed parameters will cycle in the following order:

In sync with this, there is a black arrow on the right side of the monitor that moves up and down to point to the name of the unit currently being displayed.

Zero calibration of instruments: Prolonged use of instruments may result in certain zero drift. This instrument is equipped with a zero calibration device, which can be used for zero calibration. Zero calibration should be performed when atmospheric pressure is relatively stable. Place the instrument inhPa (Bai Pa)Compare the unit status with a pressure measuring instrument that is one level higher in accuracy than this instrument (the accuracy of the reference instrument should be at least better than that of this instrument)±0.5hPa）Apply multiple observations (at least)5Calculate the difference in air pressure measurement based on the average value of (more than) times:

difference=Standard instrument reading-The reading of this instrument

Pay attention to the circuit board6Digital switch, as shown in the figure2As shown:

front5A switch（1 – 5）Indicates the amount of correction, while the6A switch indicates the direction of correction (plus or minus).

switch1-5Each represents the weight of the correction amount 2⁰、2¹、2²、2³、2⁴ That is to say 1、2、4、8、16） If the switch is reversed‘0’If the position is not corrected, it will be reversed‘1’The position indicates the correction for that position.

第6If the position switch is reversed’+’Position is represented by adding a correction amount to the measurement result, if reversed‘-’The position is represented by subtracting the correction amount from the measurement result,The unit of correction quantity is0.1 hPa.

Example of zero position correction: see figure3The positions of the switches shown.

When making actual corrections, the original correction amount (plus correction) should be read out on the correction amount setting switch first+Add the difference obtained from the comparison measurement just now to this correction (minus correction to negative), and calculate a new correction. Then reset the setting switch according to this new correction amount.Attention: The new correction setting value will only be effective after the power is reconnected.