diff --git a/app/src/main/java/com/yinuo/safetywatcher/watcher/port/GasUtilss.kt b/app/src/main/java/com/yinuo/safetywatcher/watcher/port/GasUtilss.kt
index 1a05361..69f468d 100644
--- a/app/src/main/java/com/yinuo/safetywatcher/watcher/port/GasUtilss.kt
+++ b/app/src/main/java/com/yinuo/safetywatcher/watcher/port/GasUtilss.kt
@@ -115,20 +115,21 @@ fun getGasHighThreshold(gasType: String, unit: String): Float {
  * 获取本地气体单位
  */
 fun getLocalGasUnit(gasType: String): String {
-    return when (gasType.uppercase()) {
-        O2 -> UNIT_VOL
-        VOCS -> UNIT_MGM3 // TODO
-        CO, CH4, H2S, H2, NH3, S02, CL2, NO2, NO, HF, C02 -> getDefaultUnit(gasType)
-        else -> ""
+    val localUnit = MMKVUtils.getString("unit_$gasType")
+    if (!localUnit.isNullOrEmpty()) {
+        return localUnit
     }
+    return getDefaultUnit(gasType)
 }
 
 private fun getDefaultUnit(gasType: String): String {
-    val localUnit = MMKVUtils.getString("unit_$gasType")
-    if (!localUnit.isNullOrEmpty()) {
-        return localUnit
+    return when (gasType.uppercase()) {
+        O2 -> UNIT_VOL
+        CH4, H2 -> UNIT_LEL
+        VOCS -> UNIT_PPM
+        CO, H2S, NH3, S02, CL2, NO2, NO, HF, C02 -> UNIT_PPM
+        else -> UNIT_PPM
     }
-    return UNIT_PPM
 }
 
 fun saveGasUnit(gasType: String, unit: String) {
diff --git a/app/src/main/java/com/yinuo/safetywatcher/watcher/ui/SensorSettingActivity.kt b/app/src/main/java/com/yinuo/safetywatcher/watcher/ui/SensorSettingActivity.kt
index d92f69d..9141ec1 100644
--- a/app/src/main/java/com/yinuo/safetywatcher/watcher/ui/SensorSettingActivity.kt
+++ b/app/src/main/java/com/yinuo/safetywatcher/watcher/ui/SensorSettingActivity.kt
@@ -11,7 +11,10 @@ import com.yinuo.safetywatcher.watcher.base.NoOptionsActivity
 import com.yinuo.safetywatcher.watcher.port.GasCache
 import com.yinuo.safetywatcher.watcher.port.UNIT_MGM3
 import com.yinuo.safetywatcher.watcher.port.UNIT_PPM
+import com.yinuo.safetywatcher.watcher.port.cmd.CH4
+import com.yinuo.safetywatcher.watcher.port.cmd.H2
 import com.yinuo.safetywatcher.watcher.port.cmd.O2
+import com.yinuo.safetywatcher.watcher.port.cmd.VOCS
 import com.yinuo.safetywatcher.watcher.port.getGasRange
 import com.yinuo.safetywatcher.watcher.port.getLocalGasUnit
 import com.yinuo.safetywatcher.watcher.port.saveGasUnit
@@ -44,10 +47,20 @@ class SensorSettingActivity : NoOptionsActivity() {
         // 氧气单位固定
         if (gasName == O2) {
             mBinding.rgUnit.visibility = View.GONE
+            mBinding.rbLel.visibility = View.GONE
             mBinding.rbVol.visibility = View.VISIBLE
-        } else {
+        } else if (gasName == CH4 || gasName == H2){
+            mBinding.rgUnit.visibility = View.GONE
+            mBinding.rbVol.visibility = View.GONE
+            mBinding.rbLel.visibility = View.VISIBLE
+        }
+        else {
             mBinding.rgUnit.visibility = View.VISIBLE
             mBinding.rbVol.visibility = View.GONE
+            mBinding.rbLel.visibility = View.GONE
+            if (gasName == VOCS){
+                mBinding.rbMgm3.visibility = View.GONE
+            }
             if (localGasUnit == UNIT_PPM) {
                 mBinding.rbPpm.isChecked = true
             } else {
diff --git a/app/src/main/res/layout/activity_sensor_setting.xml b/app/src/main/res/layout/activity_sensor_setting.xml
index 0b4f7ad..6878ef6 100644
--- a/app/src/main/res/layout/activity_sensor_setting.xml
+++ b/app/src/main/res/layout/activity_sensor_setting.xml
@@ -55,6 +55,19 @@
         android:textColor="@color/white"
         android:textSize="@dimen/_28dp" />
 
+    <androidx.appcompat.widget.AppCompatRadioButton
+        android:id="@+id/rb_lel"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="@dimen/_40dp"
+        android:layout_marginStart="@dimen/_20dp"
+        android:paddingHorizontal="@dimen/_6dp"
+        android:checked="true"
+        android:focusable="true"
+        android:text="@string/unit_lel"
+        android:textColor="@color/white"
+        android:textSize="@dimen/_28dp" />
+
     <RadioGroup
         android:id="@+id/rg_unit"
         android:layout_width="match_parent"
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 2cc0171..1ff528b 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -72,6 +72,7 @@
     <string name="unit_ppm">ppm</string>
     <string name="unit_mg_m3">mg/m3</string>
     <string name="unit_vol">%VOL</string>
+    <string name="unit_lel">%LEL</string>
     <string name="loading">加载中…</string>
 
     <string name="calibration_value">请输入校准浓度</string>