Temperature, Humidity, and Barometric Pressure Gauge

This product is capable of real-time monitoring of environmental temperature, humidity, and barometric pressure. It transmits data to the main control device via the RS485 communication protocol. It is widely used in industrial processes, meteorological monitoring, hydrology, water conservancy, geological exploration, and other fields.

1.Product Introduction

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Figure 1

Key Features:

- High quality and stability

- Integrated measurement of temperature, humidity, and barometric pressure

- RS485 interface and Modbus-RTU standard communication protocol

- Reverse polarity protection and overvoltage protection

- Fully sealed stainless steel structure with IP68 protection

2. Technical Specifications

2.1 Main Performance Indicators

Performance Indicators	Temperature	Humidity	Barometric Pressure
Accuracy	±0.1℃ (see Table 1)	1.5 %RH ，(see Table 2)	±50Pa
Range	-40~85℃	0~100%RH	300~1250hPa
Resolution	0.1℃	1%RH	1Pa

Table 1

table 2.png

Table 2

table 3.png

Table 3

2.2 Other Parameters

Electrical Characteristics
Supply Voltage	DC5～30V
Power Protection	Reverse polarity and over-voltage protection
Output Method	RS485/Modbus-RTU protocol
Structural Characteristics
Measurement Medium	Compatible with stainless steel and fluororubber
Housing Material	Stainless steel 316L
Cable Material	PVC or polyurethane
Cable Specifications	Φ7.6mm ，Φ7.6mm, custom length
Environmental Characteristics
Protection Level	IP68
Operating Environment	Operating temperature: -40 to 85℃, relative humidity: 0 to 100%RH

Figure

2.3 Power Supply and RS485 Wiring Definitions**

No.	Wire Color	Definition
1	Red	5-30V+
2	Blue	RS485+
3	Green	RS485-
4	Yellow	GND

Figure 3

2.4 Dimensions (Unit: mm）

Figure 4

table 5.png

Figure 5

3. User Instructions

3.1 Connecting to a Computer

Refer to Table 3 for wiring. The following accessories are required to connect to a computer:

- RS232 to RS485 converter

- USB to RS232 converter

- USB to RS485 converter

Connection Method:

- Connect the blue wire (RS485-A) to the converter's RS485+ (T+).

- Connect the green wire (RS485-B) to the converter's RS485- (T-).

- Plug the USB cable directly into the computer's USB port. The corresponding COM port can be viewed in the device manager and used in the computer software.

3.2 Communication Protocol**

The supported communication protocol is MODBUS-RTU. After external power is connected, the device can be operated via computer software or a Modbus host (e.g., RTU device). The device uses an industrial-grade RS485 communication interface, operating in half-duplex master-slave mode with a transmission distance of up to 1200 meters. The default baud rate is 9600, with no parity, 1 stop bit, and 8 data bits. After connecting to a computer or RTU device, communication can be performed using function codes 03H and 10H in the Modbus-RTU protocol.

Get Device Address
Modbus Command	FF 6E 00 12 00 01 9C 18
Return Value	FF 6E 02 00 01 4C FC
Data Parsing	Device address is 0X00 0X01

Table 4

Get Temperature, Humidity, and Barometric Pressure Data
Modbus Command	01 03 00 03 00 05 75 C9
Return Value	01 03 0A 00 D9 00 D8 00 17 00 01 76 73 C9 68
Data Parsing	See Table 7

Table 5

Modify Device Address
Modbus Command	01 10 00 12 00 01 02 00 02 24 E3
Return Value	01 10 00 12 00 01 A1 CC
Data Parsing	Address modified to 0X0002

Table 6

Register Address	Name	Definition
0x00~ 0x02	Reserved	Not readable or writable
0x03	Temperature 1	Barometric pressure sensor temperature data *10 (16-bit signed integer)
0x04	Temperature 2	Temperature and humidity sensor temperature data *10 (16-bit signed integer)
0x05	Humidity	Humidity data (16-bit unsigned integer)
0x06~ 0x07	Barometric pressure	Barometric pressure data (32-bit unsigned integer)
0x0C~ 0x0E	Serial No.	Device serial number
0x0F~ 0x10	Manufacturing Date	Device manufacturing date
0x11	Version Number	Device version number
0x12	Address	Device communication address (0-255, default is 1)
0x13	Baud Rate	Serial port baud rate (default is 9600)