SPECIFICATION Product Name: Dust Sensor Model No. : SM-ND-02A ( Tentative )
SMART dust sensor for air purifier Description SM-ND-02A SM-ND-02A is a dust sensor that detects the dust particle concentration in air by using optical sensing method. An infrared light emitting diode (IR LED) and a photo-sensor are optically arranged in this device. The photo-sensor detects the reflected IR LED light by dust particles in air. This dust sensor can detect the small particle like cigarette smoke and it can distinguish small particles like smoke from large house dust by pulse pattern of signal output. This sensor has the interface of PWM, UART&I²C. Features Compact size, light weight about 59(W)x H46(T)x D18(D) mm, ~23g. PWM (pulse width modulation) output (Low pulse output) UART, I 2 C(option) interface Number display P.M 2.5, P.M10 size particles Constant forced air convection flow by heater resister in dust sensor. Lead free and ROHS directive compliant Minimum particle size can be detected over 1um (House dust size: avg 20um, yellow dust size: avg 20um, cigarette dust size: avg 1um) Application Detection of dust in the air, Indoor Air quality monitoring. Air cleaner, Air purifier, Air conditioner. Display P.M2.5, P.M10 particles by optical particle countering method Display contamination particles number
Internal Schematic i IR LED Dust, Particle LED Circuit Air flow R-Heater 3.3V Regulator Stabilization of power line ripple, noise MICOM Sensitivity adjustment UART, I2C, PWM I/F I²C mode is not specified.( customer option) PWM mode : normal mode when does not use UART and I²C mode. P1: PWM output for small particle (P.M2.5 2.5um size under) P2: PWM output for large particle (P.M10 10um size under). UART mode (9600bps, 8bit data bit, no parity, 1 bit stop bit) 1 3 4 2 5 GND Vcc (+5 V) P.M 2.5 Output (P1, PWM) TXD/I²C SDA( P2,PWM) RXD/I²C Clock
1) UART mode Set P2 is changed from PWM mode to UART TXD mode SET Dust Sensor STX(2Bytes) Command(2Bytes) Checksum ETX(2Bytes) 1st 2nd 3rd 4th 5th 6th 7th 0x4E 0x49 0x55 0x52 (1st+2nd+3rd+4th) & 0xFF 0x44 0x53 Dust Sensor SET STX(2Bytes) DATA(4Bytes) Checksum ETX(2Bytes) 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 0x4E 0x49 0x55 0x52 0x4F 0x4B (1 st +2 nd +3 rd +4 th +5 th +6 th )&0xFF 0x44 0x53 2) Require 1 st measure data SET Dust Sensor STX(2Bytes) Command(2Bytes) Checksum ETX(2Bytes) 1st 2nd 3rd 4th 5th 6th 7th 0x4E 0x49 0x55 0x4F (1st+2nd+3rd+4th) & 0xFF 0x44 0x53 Dust Sensor SET STX(2Bytes) DATA(4Bytes) Checksum ETX(2Bytes) 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 0x4E 0x49 0xAA 0xBB 0xCC 0xDD (1 st +2 nd +3 rd +4 th +5 th +6 th )&0xFF 0x44 0x53 Small dust = ((0xAA(3 rd ) * 256 + 0xBB(4 th ) ) * 1000 particles/cf(cubic feet) Big dust = ((0xCC(3 rd ) * 256 + 0xDD(4 th ) ) * 1000 particles/ CF(cubic feet)
3) Require 1 second interval measure data : Sending the measure data to set at 1 second interval from dust sensor SET Dust Sensor STX(2Bytes) Command(2Bytes) Checksum ETX(2Bytes) 1st 2nd 3rd 4th 5th 6th 7th 0x4E 0x49 0x55 0x43 (1st+2nd+3rd+4th) & 0xFF 0x44 0x53 Dust Sensor SET STX(2Bytes) DATA(4Bytes) Checksum ETX(2Bytes) 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 0x4E 0x49 0xAA 0xBB 0xCC 0xDD (1 st +2 nd +3 rd +4 th +5 th +6 th )&0xFF 0x44 0x53 Small dust = ((0xAA(3 rd ) * 256 + 0xBB(4 th ) ) * 1000 particles/ CF(cubic feet) Big dust = ((0xCC(3 rd ) * 256 + 0xDD(4 th ) ) * 1000 particles/ CF(cubic feet) 4) Dust Sensor Checking, monitoring SET Dust Sensor STX(2Bytes) Command(2Bytes) Checksum ETX(2Bytes) 1st 2nd 3rd 4th 5th 6th 7th 0x4E 0x49 0x55 0x53 (1st+2nd+3rd+4th) & 0xFF 0x44 0x53 Dust Sensor SET STX(2Bytes) DATA(4Bytes) Checksum ETX(2Bytes) 0xDD(6 th ) - 0x00 : Normal status - 0x11 : Lens Cleaning - 0xF1 : Sensor Replacement 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 0x4E 0x49 0xAA 0xBB 0xCC 0xDD (1 st +2 nd +3 rd +4 th +5 th +6 th )&0xFF 0x44 0x53 0xAA * 256 + 0xBB = Operating time (unit time) Other function can be added without notification because of performance improvement of dust sensor.
Electrical Characteristic Absolute Maximum Ratings Parameter Symbol Rating Unit Supply voltage Vcc -0.3 to + 7.0 V Operating temperature Topr -10 to 60 Storage temperature Tstg -30 to 80 Operating Supply Voltage and Signal Output (Ta=25 ) Parameter Symbol Rating Unit Supply voltage Vcc DC 5 ± 5%, Ripple <100mVat 60HZ V Current Consumption Icc < 100± 5% ma Signal output P1,P2 Hi : > 4.5V, Lo : <0.7V, *1 Negative Logic Pulse output Negative Low pulse UART I²C Power up time * 120 *2 Sec * 1. Input impedance 200 kω, Pull-Up 10 kω, recommend 30sec moving average of output signal. * 2. Two minute is needed to stabilize heater resister and air flow in dust sensor. * 3. Low frequency ripple and noise of 100mV,30Hz can be affected LPO output. Please protect the power noise under 30Hz ripple of 100mV. Recommend Operating Temperature/Humidity Parameter Rating Unit Operating Temp./Humidity -10 ~ 45, < 85%RH *1, %RH *1. Dust sensor can detect the micro size water droplet, like fog and mist, as particles. Please do not use the dust sensor in fog place, hot bath place or near humidifier. But the de-solved water droplet in the high humid air is under submicron size and the dust sensor cannot detect this submicron size water droplet.
Connector Standard connector( SM-ND-02A) Connector Part No. Symbol Description Maker Connector Housing Terminal SMAW250-05G 25048HS-05 YST025 SMAW250-05G is standard type connector. 2.5mm pitch JST(S5B-EH) is option requirement. (Model Name: SM-ND-02A-J ) Connector Pin Configuration Number Symbol Pin Description YeonHo Elec.(Korea) http://www.yeonho.com/ Pin 1 GND Ground, Connect with System ground Pin 2 P2 Low pulse Signal output(p2) of large particle, active low TXD/I²C SDA UART, I²C output Pin 3 Vcc Input Supply voltage (+5 V) Pin 4 P1 Low pulse Signal output(p1) of P.M 2.5, active low Pin 5 NC no connected, RXD/I²C Clock UART, I²C Clock input Please refer the drawing for pin number sequence. For P1 and P2, Do not need to external pull up resister, internal pull up resistor is 10K.
Electro-Optical Characteristics (PWM output, UART) X axis : particles/ cubic feet, Y-axis : LPO(%) Output Uniformity : < ± 15% All dust sensor is tested at three different dust concentration for sensitivity adjustment. This figure shows PWM output deviation of ±15% maximum and minimum UART output is calibrated to follow the center blue line of figure. Distinguishing Method between small cigarette smoke and large house dust As on the below Fig.2, the output of small cigarette smoke shows narrow pulse or overlapped pulse shape continuously. But the output of large dust shows wide pulse and not overlapped. Therefore, by reading a transition of output pulse during a certain time period using system MICOM, the system can distinguish (a)kind of dust (b) Large particle (c) Small particle And the system can also detect how and how much air polluted.
Output (P1) occupancy (%) Small Particles, P.M2.5 Particles Sum (Tsp) = (T2 +T3~ T7)/Top Output (P2) occupancy (%) Large Particles < P.M10 um Sum (Tlp)= (T1 +T6+ T8)/Top Notes for application High Lo w T1 11 FiG.2 1. EMI and Power line noise protection and malfunction T op ( ~8 sec moving Avg.) T2 T3 T4 T5 T6 T7 T8 T1 T2 T3 T4 To protect EMI affection of photo sensor signal from motor and high voltage source, another bottom metal shield case could be soldered on electronic PCB s ground by customer requirements. Normally, top shield case is enough to protect EMI from outer electronic goods. However, to prevent EMI from high voltage negative ion generator and power line noise from electric dust collector, please install the high voltage generator in the opposite side from dust sensor also pay attention to prevent power line noise by using noise filter. The malfunction of dust senor can be observed by taping all holes of dust sensor completely not to penetrate dust into open holes of dust senor. After making clean the dust sensor chamber and taping all holes not to come any dusts into optical zone of sensor and operate the sensor. In this experiment dust sensor has not to show any low pulse output. If it is interrupted by EMI and line noise, many Low pulse output signal will be showed up. In this case, please consult to NIDS s technical team. T6 T8
2. Dust Sensor install Method When customer install the dust sensor in air cleaner, dust sensor must be installed vertically in the place that is not affected by air flow caused by motor fan rotation. We recommend to install dust sensor in the front panel side. The dust sensor can detect the water vapor as dust. Please do not use dust sensor in vaporizing place like bathroom or at near air humidifier. Dust sensor use IR wavelength LED and the visible cutoff photo sensor, but the irradiation by lamp light of optical zone will cause malfunction of dust sensor. Please protect the center hole shaped triangle for dust sensor optics not to irradiate directly. Please do not close the bottom and top hole for air flow to measure the dust. The center hole of PCB is for screwing bolt to system. Please use screw PH 3 pie for fixing. Please pay attention not to damage the sensor optics and cover case. The heater resister is installed inside of dust sensor for inducing the forced air convection and the heated air flows from bottom side to top side direction. The heater resister s temperature is increased over 40 than atmosphere. So, vertical positioning of dust sensor is important for air flow direction and speed optical zone. The air flow direction and flow speed can affect the signal output of dust sensor. Please keep ± 5 degree position vertically. 3. Cleaning Cigarette tar on the lens should affect the sensitivity of dust senor. Wet swab with alcohol and rub softly the lens and dry. Normally wet cleaning is not recommended, because there is a case this device is not satisfied with its characteristics by wet cleaning. If large particle such as home dust are accumulate in the dust sensor optics parts, please consider the maintenance such as vacuuming or blowing off the dust by air.
4. Sensitivity adjustment, customized low pulse output data control by MICOM programming Dust sensor sensitivity is adjusted by MICOM program. Customer cannot change the sensitivity by changing volume resister. MICOM send the low pulse output data proportional with dust concentration. Also MICOM can be programmed to send the communication code with system MICOM like code for LED level or code for monitoring sensor life. If customer wants to use dust sensor to special purpose like fire detection, MICOM program can be changed to send low pulse data for fire alarm level warning. Please contact to NIDS technical team for more information. 5. Responsibility This product shall not contain the following materials banned in RoHS Directive. (2002/95/EC) - Pb, Hg, Cd, Cr+6, PBB, PBDE NIDS takes no responsibility for any problems related to any intellectual property right of a third party resulting from the use of NIDS s device. NIDS takes no responsibility for damage caused by improper use of the device which does not meet the condition of absolute maximum ratings to be specified in relevant specification sheet nor meet the condition of the extremely high level of reliability and safety such as safety device, clean room monitoring, fire alarm, life support equipment, etc. This publication is the proprietary product of NIDS and is copyright with all rights reserved. Under the copyright laws, no part of this publication may be reproduced or transmitted in any form of or by any means, for any purpose, without the express written permission of NIDS. The express written permission is also needed before any use of this publication by a third party. Please contact with a NIDS representative if there are any questions for this publication. Test Standard for dust sensor calibration The first standard is the certificated particle counter. (Metone, HACC) The second standard is the master dust sensor and the master dust sensor is always used for the process quality control of production. This master dust sensor will be compared with the customer master sensor once every six month. All dust sensor is calibrated by MICOM auto calibration program of dust sensor.
Reliability 1 Drop 2 High temp. Storage 3 Low temp. storage 4 Thermal Cycle 5 Thermal Shock Drop it unintentionally from 100cm height down to the hard wooden board three times at random direction Leave in the atmosphere 80 for 1,000 hours Leave in the atmosphere -30 for 1,000 hour Repeat 20 times in the following cycle. Repeat 20 times in the following cycle. - No damage, - No breakage, - Output Within ±30% of the initial LPO of sample) N=10 6 High Temp. Operation Operating it in the atmosphere of 60 for 1000 hours 7 Low Temp. Operation Operating it in the atmosphere of -10 for 1000 hours 8 Mechanical shock Frequency : 5~55~5Hz Acceleration : 21.6m/s^2(2.2G) Direction : X,Y,Z direction for 2 hours N=2
Packaging Specification BOX 395*395* 410 mm3 400pcs / box (~12kg) 395*395*265 mm3 200pcs /box (~7kg) Outline Dimension Notice : This document can be changed without notice for the improved properties. Technical Information Contact sunny@nids.co.kr