SONBEST SM1911M User manual
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SM1911M
4-20mA current type temperature and humidity sensor
User Manual
File Version: V22.1.17
SM1911M using the standard DC4-20mA current output signal,easyaccess to PLC，DCS and other
instruments or systemsfor monitoring temperature,humidity state quantities.The internaluse of
high-precision sensing core and related devices to ensure high reliability and excellent long-term
stability,can be customized RS232,RS485,CAN,4-20mA,DC0~5V\10V,ZIGBEE,Lora,WIFI,GPRSand
other output methods.
Technical Parameters
Technical parameter
Parameter value
SM1911M Us e r Ma nual http://www.sonbus.com/
Sha nghaiSonbest Industrial Co., Ltd Page2
Brand
SONBEST
Temperature measuringrange
-30℃~80℃
Temperature measuringaccuracy
±0.5℃@25℃
Humidity measuring range
0~100%RH
Humidity accuracy
±3%RH @25℃
Communication Interface
DC4~20mA
Power
DC12~24V 1A
Running temperature
-40~80°C
Working humidity
5%RH~90%RH
Wiringinstructions
Any incorrect wiring can cause irreversible damage to the product. Please carefully wire the cable as
follows in the case of power failure, and then connect the cable to confirm the correctness and then use it
again.
ID
Core color
Identification
Note
1
Red
V+
Power V+
2
Green
V-
Power V-
3
Yellow
I1+
sensor 1 output
4
Blue
I2+
sensor 2 output
In the case of broken wires, wire the wires as shown in the figure. If the product itself has no leads, the
core color is for reference.
1. temperature and current computing
relationship
For example, the range is -30~80℃, the analog output is 4~20mAcurrent signal, temperature and
current The calculation relationship is as shown in the formula: C = (A2-A1) * (X-B1) / (B2-B1) + A1, where
A2 is temperature range upper limit, A1 isthe lower limitof the range, B2 is current output range upper limit,
B1 is the lower limit, X is the currently read temperature value, and Cis the calculated current value. The
list of commonly used values is as follows:
current(mA)
temperatureValue (℃)
Calculation Process
4
-30
(80-(-30))*(4-4)÷ (20-4)+-30
5
-23.125
(80-(-30))*(5-4)÷ (20-4)+-30
6
-16.25
(80-(-30))*(6-4)÷ (20-4)+-30
7
-9.375
(80-(-30))*(7-4)÷ (20-4)+-30
8
-2.5
(80-(-30))*(8-4)÷ (20-4)+-30
9
4.375
(80-(-30))*(9-4)÷ (20-4)+-30
10
11.25
(80-(-30))*(10-4)÷ (20-4)+-30
11
18.125
(80-(-30))*(11-4)÷ (20-4)+-30
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12
25
(80-(-30))*(12-4)÷ (20-4)+-30
13
31.875
(80-(-30))*(13-4)÷ (20-4)+-30
14
38.75
(80-(-30))*(14-4)÷ (20-4)+-30
15
45.625
(80-(-30))*(15-4)÷ (20-4)+-30
16
52.5
(80-(-30))*(16-4)÷ (20-4)+-30
17
59.375
(80-(-30))*(17-4)÷ (20-4)+-30
18
66.25
(80-(-30))*(18-4)÷ (20-4)+-30
19
73.125
(80-(-30))*(19-4)÷ (20-4)+-30
20
80
(80-(-30))*(20-4)÷ (20-4)+-30
As shown in the above formula, when measuring 8mA, current current is 31.5℃。
2. humidity and current computing relationship
For example, the range is 0~100%RH, the analog output is 4~20mAcurrent signal, humidity and
current The calculation relationship is as shown in the formula: C = (A2-A1) * (X-B1) / (B2-B1) + A1, where
A2 is humidity range upper limit, A1 is the lower limit of the range, B2 is current output range upper limit, B1
is the lower limit, X is the currentlyread humidity value, and C is the calculated current value. The list of
commonly used values is as follows:
current(mA)
humidityValue (%RH)
Calculation Process
4
0.0
(100-0)*(4-4)÷ (20-4)+0
5
6.3
(100-0)*(5-4)÷ (20-4)+0
6
12.5
(100-0)*(6-4)÷ (20-4)+0
7
18.8
(100-0)*(7-4)÷ (20-4)+0
8
25.0
(100-0)*(8-4)÷ (20-4)+0
9
31.3
(100-0)*(9-4)÷ (20-4)+0
10
37.5
(100-0)*(10-4)÷ (20-4)+0
11
43.8
(100-0)*(11-4)÷ (20-4)+0
12
50.0
(100-0)*(12-4)÷ (20-4)+0
13
56.3
(100-0)*(13-4)÷ (20-4)+0
14
62.5
(100-0)*(14-4)÷ (20-4)+0
15
68.8
(100-0)*(15-4)÷ (20-4)+0
16
75.0
(100-0)*(16-4)÷ (20-4)+0
17
81.3
(100-0)*(17-4)÷ (20-4)+0
18
87.5
(100-0)*(18-4)÷ (20-4)+0
19
93.8
(100-0)*(19-4)÷ (20-4)+0
20
100.0
(100-0)*(20-4)÷ (20-4)+0
As shown in the above formula, when measuring 8mA, current current is 29%RH。
Disclaimer
This document provides all information about the product, does not grant any license to intellectual
property, does not express or imply, and prohibits any other means of granting any intellectual property
rights, such as the statement of sales terms and conditions of this product, other issues. No liability is
assumed. Furthermore, our company makes no warranties, express or implied, regarding the sale and use
of this product, including the suitability for the specific use of the product, the marketability or the
infringement liability for any patent, copyright or other intellectual property rights, etc. Product
specifications and product descriptions may be modified at any time without notice.
SM1911M Us e r Ma nual http://www.sonbus.com/
Sha nghaiSonbest Industrial Co., Ltd Page4
Contact Us
Company: Shanghai Sonbest Industrial Co., Ltd
Address:Building 8,No.215 North east road,Baoshan District,Shanghai,China
Web: http://www.sonbest.com
Web: http://www.sonbus.com
SKYPE: soobuu
Email: sale@sonbest.com
Tel: 86-021-51083595 / 66862055 / 66862075 /66861077
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