diff --git a/examples/BASIC_v4/BASIC_v4.ino b/examples/BASIC_v4/BASIC_v4.ino
index cc0dc1c..43a61c4 100644
--- a/examples/BASIC_v4/BASIC_v4.ino
+++ b/examples/BASIC_v4/BASIC_v4.ino
@@ -50,7 +50,7 @@ CC BY-SA 4.0 Attribution-ShareAlike 4.0 International License
 #define SENSOR_TVOC_UPDATE_INTERVAL 1000     /** ms */
 #define SENSOR_CO2_UPDATE_INTERVAL 5000      /** ms */
 #define SENSOR_PM_UPDATE_INTERVAL 5000       /** ms */
-#define SENSOR_TEMP_HUM_UPDATE_INTERVAL 5000 /** ms */
+#define SENSOR_TEMP_HUM_UPDATE_INTERVAL 2000 /** ms */
 #define DISPLAY_DELAY_SHOW_CONTENT_MS 2000   /** ms */
 #define WIFI_HOTSPOT_PASSWORD_DEFAULT                                          \
   "cleanair" /** default WiFi AP password                                      \
@@ -115,7 +115,7 @@ public:
    * @return true Success
    * @return false Failure
    */
-  bool pollServerConfig(String id) {
+  bool fetchServerConfigure(String id) {
     String uri =
         "http://hw.airgradient.com/sensors/airgradient:" + id + "/one/config";
 
@@ -368,10 +368,10 @@ static bool wifiHasConfig = false; /** */
 static void boardInit(void);
 static void failedHandler(String msg);
 static void co2Calibration(void);
-static void serverConfigPoll(void);
-static void co2Poll(void);
-static void pmPoll(void);
-static void tempHumPoll(void);
+static void serverConfigUpdate(void);
+static void co2Update(void);
+static void pmUpdate(void);
+static void tempHumUpdate(void);
 static void sendDataToServer(void);
 static void dispHandler(void);
 static String getDevId(void);
@@ -382,12 +382,12 @@ bool hasSensorS8 = true;
 bool hasSensorPMS = true;
 bool hasSensorSHT = true;
 int pmFailCount = 0;
-AgSchedule configSchedule(SERVER_CONFIG_UPDATE_INTERVAL, serverConfigPoll);
+AgSchedule configSchedule(SERVER_CONFIG_UPDATE_INTERVAL, serverConfigUpdate);
 AgSchedule serverSchedule(SERVER_SYNC_INTERVAL, sendDataToServer);
 AgSchedule dispSchedule(DISP_UPDATE_INTERVAL, dispHandler);
-AgSchedule co2Schedule(SENSOR_CO2_UPDATE_INTERVAL, co2Poll);
-AgSchedule pmsSchedule(SENSOR_PM_UPDATE_INTERVAL, pmPoll);
-AgSchedule tempHumSchedule(SENSOR_TEMP_HUM_UPDATE_INTERVAL, tempHumPoll);
+AgSchedule co2Schedule(SENSOR_CO2_UPDATE_INTERVAL, co2Update);
+AgSchedule pmsSchedule(SENSOR_PM_UPDATE_INTERVAL, pmUpdate);
+AgSchedule tempHumSchedule(SENSOR_TEMP_HUM_UPDATE_INTERVAL, tempHumUpdate);
 
 void setup() {
   Serial.begin(115200);
@@ -413,7 +413,7 @@ void setup() {
     wifiHasConfig = true;
     sendPing();
 
-    agServer.pollServerConfig(getDevId());
+    agServer.fetchServerConfigure(getDevId());
     if (agServer.isCo2Calib()) {
       co2Calibration();
     }
@@ -576,8 +576,8 @@ static void co2Calibration(void) {
   }
 }
 
-static void serverConfigPoll(void) {
-  if (agServer.pollServerConfig(getDevId())) {
+static void serverConfigUpdate(void) {
+  if (agServer.fetchServerConfigure(getDevId())) {
     if (agServer.isCo2Calib()) {
       if (hasSensorS8) {
         co2Calibration();
@@ -609,12 +609,12 @@ static void serverConfigPoll(void) {
   }
 }
 
-static void co2Poll() {
+static void co2Update() {
   co2Ppm = ag.s8.getCo2();
   Serial.printf("CO2 index: %d\r\n", co2Ppm);
 }
 
-void pmPoll() {
+void pmUpdate() {
   if (ag.pms5003.readData()) {
     pm25 = ag.pms5003.getPm25Ae();
     Serial.printf("PMS2.5: %d\r\n", pm25);
@@ -628,7 +628,7 @@ void pmPoll() {
   }
 }
 
-static void tempHumPoll() {
+static void tempHumUpdate() {
   if (ag.sht.measure()) {
     temp = ag.sht.getTemperature();
     hum = ag.sht.getRelativeHumidity();
diff --git a/examples/ONE_I-9PSL/ONE_I-9PSL.ino b/examples/ONE_I-9PSL/ONE_I-9PSL.ino
index 55f435e..c7955d6 100644
--- a/examples/ONE_I-9PSL/ONE_I-9PSL.ino
+++ b/examples/ONE_I-9PSL/ONE_I-9PSL.ino
@@ -98,7 +98,7 @@ enum {
 #define SENSOR_TVOC_UPDATE_INTERVAL 1000     /** ms */
 #define SENSOR_CO2_UPDATE_INTERVAL 5000      /** ms */
 #define SENSOR_PM_UPDATE_INTERVAL 5000       /** ms */
-#define SENSOR_TEMP_HUM_UPDATE_INTERVAL 5000 /** ms */
+#define SENSOR_TEMP_HUM_UPDATE_INTERVAL 2000 /** ms */
 #define DISPLAY_DELAY_SHOW_CONTENT_MS 2000   /** ms */
 #define WIFI_HOTSPOT_PASSWORD_DEFAULT                                          \
   "cleanair" /** default WiFi AP password                                      \
@@ -167,13 +167,14 @@ public:
   }
 
   /**
-   * @brief Get server configuration
+   * @brief Fetch server configuration, if get sucessed and configuratrion
+   * parameter has changed store into local storage
    *
    * @param id Device ID
    * @return true Success
    * @return false Failure
    */
-  bool pollServerConfig(String id) {
+  bool fetchServerConfigure(String id) {
     String uri =
         "http://hw.airgradient.com/sensors/airgradient:" + id + "/one/config";
 
@@ -680,7 +681,7 @@ static String wifiSSID = "";
 
 static void boardInit(void);
 static void failedHandler(String msg);
-static void serverConfigPoll(void);
+static void serverConfigUpdate(void);
 static void co2Calibration(void);
 static void setRGBledPMcolor(int pm25Value);
 static void ledSmHandler(int sm);
@@ -690,12 +691,12 @@ static void sensorLedColorHandler(void);
 static void appLedHandler(void);
 static void appDispHandler(void);
 static void updateWiFiConnect(void);
-static void updateDispLedBar(void);
-static void tvocPoll(void);
-static void pmPoll(void);
+static void displayAndLedBarUpdate(void);
+static void tvocUpdate(void);
+static void pmUpdate(void);
 static void sendDataToServer(void);
-static void tempHumPoll(void);
-static void co2Poll(void);
+static void tempHumUpdate(void);
+static void co2Update(void);
 static void showNr(void);
 static void webServerInit(void);
 static String getServerSyncData(bool localServer);
@@ -709,13 +710,13 @@ bool hasSensorSGP = true;
 bool hasSensorSHT = true;
 int pmFailCount = 0;
 uint32_t factoryBtnPressTime = 0;
-AgSchedule dispLedSchedule(DISP_UPDATE_INTERVAL, updateDispLedBar);
-AgSchedule configSchedule(SERVER_CONFIG_UPDATE_INTERVAL, serverConfigPoll);
+AgSchedule dispLedSchedule(DISP_UPDATE_INTERVAL, displayAndLedBarUpdate);
+AgSchedule configSchedule(SERVER_CONFIG_UPDATE_INTERVAL, serverConfigUpdate);
 AgSchedule serverSchedule(SERVER_SYNC_INTERVAL, sendDataToServer);
-AgSchedule co2Schedule(SENSOR_CO2_UPDATE_INTERVAL, co2Poll);
-AgSchedule pmsSchedule(SENSOR_PM_UPDATE_INTERVAL, pmPoll);
-AgSchedule tempHumSchedule(SENSOR_TEMP_HUM_UPDATE_INTERVAL, tempHumPoll);
-AgSchedule tvocSchedule(SENSOR_TVOC_UPDATE_INTERVAL, tvocPoll);
+AgSchedule co2Schedule(SENSOR_CO2_UPDATE_INTERVAL, co2Update);
+AgSchedule pmsSchedule(SENSOR_PM_UPDATE_INTERVAL, pmUpdate);
+AgSchedule tempHumSchedule(SENSOR_TEMP_HUM_UPDATE_INTERVAL, tempHumUpdate);
+AgSchedule tvocSchedule(SENSOR_TVOC_UPDATE_INTERVAL, tvocUpdate);
 
 void setup() {
   EEPROM.begin(512);
@@ -785,7 +786,7 @@ void setup() {
     Serial.println(WiFi.localIP());
 
     /** Get first connected to wifi */
-    agServer.pollServerConfig(getDevId());
+    agServer.fetchServerConfigure(getDevId());
     if (agServer.isConfigFailed()) {
       dispSmHandler(APP_SM_WIFI_OK_SERVER_OK_SENSOR_CONFIG_FAILED);
       ledSmHandler(APP_SM_WIFI_OK_SERVER_OK_SENSOR_CONFIG_FAILED);
@@ -903,7 +904,7 @@ static void ledTest2Min(void) {
   }
 }
 
-static void co2Poll(void) {
+static void co2Update(void) {
   co2Ppm = ag.s8.getCo2();
   Serial.printf("CO2 index: %d\r\n", co2Ppm);
 }
@@ -917,14 +918,15 @@ void webServerMeasureCurrentGet(void) {
 /**
  * Sends metrics in Prometheus/OpenMetrics format to the currently connected
  * webServer client.
- * 
- * For background, see: https://prometheus.io/docs/instrumenting/exposition_formats/
+ *
+ * For background, see:
+ * https://prometheus.io/docs/instrumenting/exposition_formats/
  */
 void webServerMetricsGet(void) {
   String response;
   String current_metric_name;
-  const auto add_metric = [&](const String &name, const String &help, const String &type, const String &unit = "")
-  {
+  const auto add_metric = [&](const String &name, const String &help,
+                              const String &type, const String &unit = "") {
     current_metric_name = "airgradient_" + name;
     if (!unit.isEmpty())
       current_metric_name += "_" + unit;
@@ -938,69 +940,114 @@ void webServerMetricsGet(void) {
   };
 
   add_metric("info", "AirGradient device information", "info");
-  add_metric_point("airgradient_serial_number=\"" + getDevId() + "\",airgradient_device_type=\"ONE_I-9PSL\",airgradient_library_version=\"" + ag.getVersion() + "\"", "1");
+  add_metric_point("airgradient_serial_number=\"" + getDevId() +
+                       "\",airgradient_device_type=\"" + ag.getBoardName() +
+                       "\",airgradient_library_version=\"" + ag.getVersion() +
+                       "\"",
+                   "1");
 
-  add_metric("config_ok", "1 if the AirGradient device was able to successfully fetch its configuration from the server", "gauge");
+  add_metric("config_ok",
+             "1 if the AirGradient device was able to successfully fetch its "
+             "configuration from the server",
+             "gauge");
   add_metric_point("", agServer.isConfigFailed() ? "0" : "1");
 
-  add_metric("post_ok", "1 if the AirGradient device was able to successfully send to the server", "gauge");
+  add_metric(
+      "post_ok",
+      "1 if the AirGradient device was able to successfully send to the server",
+      "gauge");
   add_metric_point("", agServer.isServerFailed() ? "0" : "1");
 
-  add_metric("wifi_rssi", "WiFi signal strength from the AirGradient device perspective, in dBm", "gauge", "dbm");
+  add_metric(
+      "wifi_rssi",
+      "WiFi signal strength from the AirGradient device perspective, in dBm",
+      "gauge", "dbm");
   add_metric_point("", String(WiFi.RSSI()));
 
   if (hasSensorS8 && co2Ppm >= 0) {
-    add_metric("co2", "Carbon dioxide concentration as measured by the AirGradient S8 sensor, in parts per million", "gauge", "ppm");
+    add_metric("co2",
+               "Carbon dioxide concentration as measured by the AirGradient S8 "
+               "sensor, in parts per million",
+               "gauge", "ppm");
     add_metric_point("", String(co2Ppm));
   }
 
   if (hasSensorPMS) {
     if (pm01 >= 0) {
-      add_metric("pm1", "PM1.0 concentration as measured by the AirGradient PMS sensor, in micrograms per cubic meter", "gauge", "ugm3");
+      add_metric("pm1",
+                 "PM1.0 concentration as measured by the AirGradient PMS "
+                 "sensor, in micrograms per cubic meter",
+                 "gauge", "ugm3");
       add_metric_point("", String(pm01));
     }
     if (pm25 >= 0) {
-      add_metric("pm2d5", "PM2.5 concentration as measured by the AirGradient PMS sensor, in micrograms per cubic meter", "gauge", "ugm3");
+      add_metric("pm2d5",
+                 "PM2.5 concentration as measured by the AirGradient PMS "
+                 "sensor, in micrograms per cubic meter",
+                 "gauge", "ugm3");
       add_metric_point("", String(pm25));
     }
     if (pm10 >= 0) {
-      add_metric("pm10", "PM10 concentration as measured by the AirGradient PMS sensor, in micrograms per cubic meter", "gauge", "ugm3");
+      add_metric("pm10",
+                 "PM10 concentration as measured by the AirGradient PMS "
+                 "sensor, in micrograms per cubic meter",
+                 "gauge", "ugm3");
       add_metric_point("", String(pm10));
     }
     if (pm03PCount >= 0) {
-      add_metric("pm0d3", "PM0.3 concentration as measured by the AirGradient PMS sensor, in number of particules per 100 milliliters", "gauge", "p100ml");
+      add_metric("pm0d3",
+                 "PM0.3 concentration as measured by the AirGradient PMS "
+                 "sensor, in number of particules per 100 milliliters",
+                 "gauge", "p100ml");
       add_metric_point("", String(pm03PCount));
     }
   }
 
   if (hasSensorSGP) {
     if (tvocIndex >= 0) {
-      add_metric("tvoc_index", "The processed Total Volatile Organic Compounds (TVOC) index as measured by the AirGradient SGP sensor", "gauge");
+      add_metric("tvoc_index",
+                 "The processed Total Volatile Organic Compounds (TVOC) index "
+                 "as measured by the AirGradient SGP sensor",
+                 "gauge");
       add_metric_point("", String(tvocIndex));
     }
     if (tvocRawIndex >= 0) {
-      add_metric("tvoc_raw_index", "The raw input value to the Total Volatile Organic Compounds (TVOC) index as measured by the AirGradient SGP sensor", "gauge");
+      add_metric("tvoc_raw_index",
+                 "The raw input value to the Total Volatile Organic Compounds "
+                 "(TVOC) index as measured by the AirGradient SGP sensor",
+                 "gauge");
       add_metric_point("", String(tvocRawIndex));
     }
     if (noxIndex >= 0) {
-      add_metric("nox_index", "The processed Nitrous Oxide (NOx) index as measured by the AirGradient SGP sensor", "gauge");
+      add_metric("nox_index",
+                 "The processed Nitrous Oxide (NOx) index as measured by the "
+                 "AirGradient SGP sensor",
+                 "gauge");
       add_metric_point("", String(noxIndex));
     }
   }
 
   if (hasSensorSHT) {
     if (temp > -1001) {
-      add_metric("temperature", "The ambient temperature as measured by the AirGradient SHT sensor, in degrees Celsius", "gauge", "degc");
+      add_metric("temperature",
+                 "The ambient temperature as measured by the AirGradient SHT "
+                 "sensor, in degrees Celsius",
+                 "gauge", "degc");
       add_metric_point("", String(temp));
     }
     if (hum >= 0) {
-      add_metric("humidity", "The relative humidity as measured by the AirGradient SHT sensor", "gauge", "percent");
+      add_metric(
+          "humidity",
+          "The relative humidity as measured by the AirGradient SHT sensor",
+          "gauge", "percent");
       add_metric_point("", String(hum));
     }
   }
 
   response += "# EOF\n";
-  webServer.send(200, "application/openmetrics-text; version=1.0.0; charset=utf-8", response);
+  webServer.send(200,
+                 "application/openmetrics-text; version=1.0.0; charset=utf-8",
+                 response);
 }
 
 void webServerHandler(void *param) {
@@ -1674,8 +1721,8 @@ static void failedHandler(String msg) {
 /**
  * @brief Send data to server
  */
-static void serverConfigPoll(void) {
-  if (agServer.pollServerConfig(getDevId())) {
+static void serverConfigUpdate(void) {
+  if (agServer.fetchServerConfigure(getDevId())) {
     if (agServer.isCo2Calib()) {
       if (hasSensorS8) {
         co2Calibration();
@@ -2113,7 +2160,7 @@ static void updateWiFiConnect(void) {
  * @brief APP display and LED handler
  *
  */
-static void updateDispLedBar(void) {
+static void displayAndLedBarUpdate(void) {
   if (factoryBtnPressTime == 0) {
     appDispHandler();
   }
@@ -2124,7 +2171,7 @@ static void updateDispLedBar(void) {
  * @brief Update tvocIndexindex
  *
  */
-static void tvocPoll(void) {
+static void tvocUpdate(void) {
   tvocIndex = ag.sgp41.getTvocIndex();
   tvocRawIndex = ag.sgp41.getTvocRaw();
   noxIndex = ag.sgp41.getNoxIndex();
@@ -2139,7 +2186,7 @@ static void tvocPoll(void) {
  * @brief Update PMS data
  *
  */
-static void pmPoll(void) {
+static void pmUpdate(void) {
   if (ag.pms5003.readData()) {
     pm01 = ag.pms5003.getPm01Ae();
     pm25 = ag.pms5003.getPm25Ae();
@@ -2180,7 +2227,7 @@ static void sendDataToServer(void) {
 /**
  * @brief Update temperature and humidity value
  */
-static void tempHumPoll(void) {
+static void tempHumUpdate(void) {
   if (ag.sht.measure()) {
 
     temp = ag.sht.getTemperature();
diff --git a/examples/Open_Air/Open_Air.ino b/examples/Open_Air/Open_Air.ino
index 5bda9ba..c1cc73d 100644
--- a/examples/Open_Air/Open_Air.ino
+++ b/examples/Open_Air/Open_Air.ino
@@ -99,7 +99,7 @@ enum {
 #define SENSOR_TVOC_UPDATE_INTERVAL 1000     /** ms */
 #define SENSOR_CO2_UPDATE_INTERVAL 5000      /** ms */
 #define SENSOR_PM_UPDATE_INTERVAL 5000       /** ms */
-#define SENSOR_TEMP_HUM_UPDATE_INTERVAL 5000 /** ms */
+#define SENSOR_TEMP_HUM_UPDATE_INTERVAL 2000 /** ms */
 #define DISPLAY_DELAY_SHOW_CONTENT_MS 2000   /** ms */
 #define WIFI_HOTSPOT_PASSWORD_DEFAULT                                          \
   "cleanair" /** default WiFi AP password                                      \
@@ -175,7 +175,7 @@ public:
    * @return true Success
    * @return false Failure
    */
-  bool pollServerConfig(String id) {
+  bool fetchServerConfigure(String id) {
     String uri =
         "http://hw.airgradient.com/sensors/airgradient:" + id + "/one/config";
 
@@ -709,11 +709,11 @@ void failedHandler(String msg);
 void co2Calibration(void);
 static String getDevId(void);
 static void updateWiFiConnect(void);
-static void tvocPoll(void);
-static void pmPoll(void);
+static void tvocUpdate(void);
+static void pmUpdate(void);
 static void sendDataToServer(void);
-static void co2Poll(void);
-static void serverConfigPoll(void);
+static void co2Update(void);
+static void serverConfigUpdate(void);
 static const char *getFwMode(int mode);
 static void showNr(void);
 static void webServerInit(void);
@@ -726,11 +726,11 @@ bool hasSensorPMS1 = true;
 bool hasSensorPMS2 = true;
 bool hasSensorSGP = true;
 uint32_t factoryBtnPressTime = 0;
-AgSchedule configSchedule(SERVER_CONFIG_UPDATE_INTERVAL, serverConfigPoll);
+AgSchedule configSchedule(SERVER_CONFIG_UPDATE_INTERVAL, serverConfigUpdate);
 AgSchedule serverSchedule(SERVER_SYNC_INTERVAL, sendDataToServer);
-AgSchedule co2Schedule(SENSOR_CO2_UPDATE_INTERVAL, co2Poll);
-AgSchedule pmsSchedule(SENSOR_PM_UPDATE_INTERVAL, pmPoll);
-AgSchedule tvocSchedule(SENSOR_TVOC_UPDATE_INTERVAL, tvocPoll);
+AgSchedule co2Schedule(SENSOR_CO2_UPDATE_INTERVAL, co2Update);
+AgSchedule pmsSchedule(SENSOR_PM_UPDATE_INTERVAL, pmUpdate);
+AgSchedule tvocSchedule(SENSOR_TVOC_UPDATE_INTERVAL, tvocUpdate);
 
 void setup() {
   EEPROM.begin(512);
@@ -764,7 +764,7 @@ void setup() {
     wifiHasConfig = true;
     sendPing();
 
-    agServer.pollServerConfig(getDevId());
+    agServer.fetchServerConfigure(getDevId());
     if (agServer.isConfigFailed()) {
       ledSmHandler(APP_SM_WIFI_OK_SERVER_OK_SENSOR_CONFIG_FAILED);
       delay(DISPLAY_DELAY_SHOW_CONTENT_MS);
@@ -1011,7 +1011,7 @@ static void updateWiFiConnect(void) {
  * @brief Update tvocIndexindex
  *
  */
-static void tvocPoll(void) {
+static void tvocUpdate(void) {
   tvocIndex = ag.sgp41.getTvocIndex();
   tvocRawIndex = ag.sgp41.getTvocRaw();
   noxIndex = ag.sgp41.getNoxIndex();
@@ -1026,7 +1026,7 @@ static void tvocPoll(void) {
  * @brief Update PMS data
  *
  */
-static void pmPoll(void) {
+static void pmUpdate(void) {
   bool pmsResult_1 = false;
   bool pmsResult_2 = false;
   if (hasSensorPMS1 && ag.pms5003t_1.readData()) {
@@ -1134,13 +1134,13 @@ static void pmPoll(void) {
   }
 }
 
-static void co2Poll(void) {
+static void co2Update(void) {
   co2Ppm = ag.s8.getCo2();
   Serial.printf("CO2 index: %d\r\n", co2Ppm);
 }
 
-static void serverConfigPoll(void) {
-  if (agServer.pollServerConfig(getDevId())) {
+static void serverConfigUpdate(void) {
+  if (agServer.fetchServerConfigure(getDevId())) {
     /** Only support CO2 S8 sensor on FW_MODE_PST */
     if (fw_mode == FW_MODE_PST) {
       if (agServer.isCo2Calib()) {
diff --git a/src/PMS/PMS5003.cpp b/src/PMS/PMS5003.cpp
index 128d1b1..268f9bb 100644
--- a/src/PMS/PMS5003.cpp
+++ b/src/PMS/PMS5003.cpp
@@ -1,5 +1,6 @@
 #include "PMS5003.h"
 #include "Arduino.h"
+#include "PMSUtils.h"
 
 #if defined(ESP8266)
 #include <SoftwareSerial.h>
@@ -63,7 +64,8 @@ bool PMS5003::begin(void) {
 
 #if defined(ESP8266)
   bsp->Pms5003.uart_tx_pin;
-  SoftwareSerial *uart = new SoftwareSerial(bsp->Pms5003.uart_tx_pin, bsp->Pms5003.uart_rx_pin);
+  SoftwareSerial *uart =
+      new SoftwareSerial(bsp->Pms5003.uart_tx_pin, bsp->Pms5003.uart_rx_pin);
   uart->begin(9600);
   if (pms.begin(uart) == false) {
     AgLog("PMS failed");
@@ -81,31 +83,6 @@ bool PMS5003::begin(void) {
   return true;
 }
 
-/**
- * @brief Convert PM2.5 to US AQI
- *
- * @param pm02
- * @return int
- */
-int PMS5003::pm25ToAQI(int pm02) {
-  if (pm02 <= 12.0)
-    return ((50 - 0) / (12.0 - .0) * (pm02 - .0) + 0);
-  else if (pm02 <= 35.4)
-    return ((100 - 50) / (35.4 - 12.0) * (pm02 - 12.0) + 50);
-  else if (pm02 <= 55.4)
-    return ((150 - 100) / (55.4 - 35.4) * (pm02 - 35.4) + 100);
-  else if (pm02 <= 150.4)
-    return ((200 - 150) / (150.4 - 55.4) * (pm02 - 55.4) + 150);
-  else if (pm02 <= 250.4)
-    return ((300 - 200) / (250.4 - 150.4) * (pm02 - 150.4) + 200);
-  else if (pm02 <= 350.4)
-    return ((400 - 300) / (350.4 - 250.4) * (pm02 - 250.4) + 300);
-  else if (pm02 <= 500.4)
-    return ((500 - 400) / (500.4 - 350.4) * (pm02 - 350.4) + 400);
-  else
-    return 500;
-}
-
 /**
  * @brief Read all package data then call to @ref getPMxxx to get the target
  * data
@@ -155,7 +132,7 @@ int PMS5003::getPm03ParticleCount(void) { return pmsData.PM_RAW_0_3; }
  * @param pm25 PM2.5 index
  * @return int PM2.5 US AQI
  */
-int PMS5003::convertPm25ToUsAqi(int pm25) { return this->pm25ToAQI(pm25); }
+int PMS5003::convertPm25ToUsAqi(int pm25) { return pm25ToAQI(pm25); }
 
 /**
  * @brief Check device initialized or not
diff --git a/src/PMS/PMS5003.h b/src/PMS/PMS5003.h
index 69e6de4..15b907c 100644
--- a/src/PMS/PMS5003.h
+++ b/src/PMS/PMS5003.h
@@ -2,8 +2,8 @@
 #define _AIR_GRADIENT_PMS5003_H_
 
 #include "../Main/BoardDef.h"
-#include "Stream.h"
 #include "PMS.h"
+#include "Stream.h"
 
 /**
  * @brief The class define how to handle PMS5003 sensor bas on @ref PMS class
@@ -41,6 +41,5 @@ private:
 
   bool begin(void);
   bool isBegin(void);
-  int pm25ToAQI(int pm02);
 };
 #endif /** _AIR_GRADIENT_PMS5003_H_ */
diff --git a/src/PMS/PMS5003T.cpp b/src/PMS/PMS5003T.cpp
index 57040a5..03b0fd2 100644
--- a/src/PMS/PMS5003T.cpp
+++ b/src/PMS/PMS5003T.cpp
@@ -1,5 +1,6 @@
 #include "PMS5003T.h"
 #include "Arduino.h"
+#include "PMSUtils.h"
 
 #if defined(ESP8266)
 #include <SoftwareSerial.h>
@@ -105,31 +106,6 @@ bool PMS5003T::begin(void) {
   return true;
 }
 
-/**
- * @brief Convert PM2.5 to US AQI
- *
- * @param pm02
- * @return int
- */
-int PMS5003T::pm25ToAQI(int pm02) {
-  if (pm02 <= 12.0)
-    return ((50 - 0) / (12.0 - .0) * (pm02 - .0) + 0);
-  else if (pm02 <= 35.4)
-    return ((100 - 50) / (35.4 - 12.0) * (pm02 - 12.0) + 50);
-  else if (pm02 <= 55.4)
-    return ((150 - 100) / (55.4 - 35.4) * (pm02 - 35.4) + 100);
-  else if (pm02 <= 150.4)
-    return ((200 - 150) / (150.4 - 55.4) * (pm02 - 55.4) + 150);
-  else if (pm02 <= 250.4)
-    return ((300 - 200) / (250.4 - 150.4) * (pm02 - 150.4) + 200);
-  else if (pm02 <= 350.4)
-    return ((400 - 300) / (350.4 - 250.4) * (pm02 - 250.4) + 300);
-  else if (pm02 <= 500.4)
-    return ((500 - 400) / (500.4 - 350.4) * (pm02 - 350.4) + 400);
-  else
-    return 500;
-}
-
 /**
  * @brief Read all package data then call to @ref getPMxxx to get the target
  * data
@@ -179,7 +155,7 @@ int PMS5003T::getPm03ParticleCount(void) { return pmsData.PM_RAW_0_3; }
  * @param pm25 PM2.5 index
  * @return int PM2.5 US AQI
  */
-int PMS5003T::convertPm25ToUsAqi(int pm25) { return this->pm25ToAQI(pm25); }
+int PMS5003T::convertPm25ToUsAqi(int pm25) { return pm25ToAQI(pm25); }
 
 /**
  * @brief Get temperature, Must call this method after @ref readData() success
diff --git a/src/PMS/PMS5003T.h b/src/PMS/PMS5003T.h
index a93cd40..ec4d78e 100644
--- a/src/PMS/PMS5003T.h
+++ b/src/PMS/PMS5003T.h
@@ -1,10 +1,10 @@
 #ifndef _PMS5003T_H_
 #define _PMS5003T_H_
 
-#include <HardwareSerial.h>
 #include "../Main/BoardDef.h"
 #include "PMS.h"
 #include "Stream.h"
+#include <HardwareSerial.h>
 
 /**
  * @brief The class define how to handle PMS5003T sensor bas on @ref PMS class
@@ -42,7 +42,6 @@ private:
 #endif
 
   bool begin(void);
-  int pm25ToAQI(int pm02);
   PMS pms;
   PMS::DATA pmsData;
   bool isBegin(void);
diff --git a/src/PMS/PMSUtils.cpp b/src/PMS/PMSUtils.cpp
new file mode 100644
index 0000000..f47813f
--- /dev/null
+++ b/src/PMS/PMSUtils.cpp
@@ -0,0 +1,26 @@
+#include "PMSUtils.h"
+
+/**
+ * @brief Convert PM2.5 to US AQI
+ *
+ * @param pm02
+ * @return int
+ */
+int pm25ToAQI(int pm02) {
+  if (pm02 <= 12.0)
+    return ((50 - 0) / (12.0 - .0) * (pm02 - .0) + 0);
+  else if (pm02 <= 35.4)
+    return ((100 - 50) / (35.4 - 12.0) * (pm02 - 12.0) + 50);
+  else if (pm02 <= 55.4)
+    return ((150 - 100) / (55.4 - 35.4) * (pm02 - 35.4) + 100);
+  else if (pm02 <= 150.4)
+    return ((200 - 150) / (150.4 - 55.4) * (pm02 - 55.4) + 150);
+  else if (pm02 <= 250.4)
+    return ((300 - 200) / (250.4 - 150.4) * (pm02 - 150.4) + 200);
+  else if (pm02 <= 350.4)
+    return ((400 - 300) / (350.4 - 250.4) * (pm02 - 250.4) + 300);
+  else if (pm02 <= 500.4)
+    return ((500 - 400) / (500.4 - 350.4) * (pm02 - 350.4) + 400);
+  else
+    return 500;
+}
diff --git a/src/PMS/PMSUtils.h b/src/PMS/PMSUtils.h
new file mode 100644
index 0000000..ffb5a84
--- /dev/null
+++ b/src/PMS/PMSUtils.h
@@ -0,0 +1,6 @@
+#ifndef _PMS_UTILS_H_
+#define _PMS_UTILS_H_
+
+int pm25ToAQI(int pm02);
+
+#endif /** _PMS_UTILS_H_ */