diff --git a/lark1fq/main.c b/lark1fq/main.c
index 18b2f9b..b5745a9 100755
--- a/lark1fq/main.c
+++ b/lark1fq/main.c
@@ -54,6 +54,9 @@ void system_init(void)
     ms5611_init();
     calc_quadratic_fit_init(CALC_POINTS);
     led_det_temperature_init();
+    for (int ch = 0; ch < 4; ch++) {
+        concentration_neg_drift_compensation_init(ch);
+    }
 }
 
 int main(void)
diff --git a/lark1fq/src/cali.c b/lark1fq/src/cali.c
index 47aa2b0..4407293 100755
--- a/lark1fq/src/cali.c
+++ b/lark1fq/src/cali.c
@@ -368,6 +368,8 @@ uint8_t cali_zero_activate(uint8_t ch)
     if (flag_cali_by_button == 0) {
         data_cali_flash.word_remain = CALI_FLASH_WORD_CNT;
     }
+    /* reset negative drift compensation to default state */
+    concentration_neg_drift_compensation_init(ch);
 
     return 0;
 }
diff --git a/lark1fq/src/concentration.c b/lark1fq/src/concentration.c
index 5c300a5..d6abe74 100755
--- a/lark1fq/src/concentration.c
+++ b/lark1fq/src/concentration.c
@@ -4,6 +4,7 @@
 #include "concentration.h"
 
 struct data_lookup_table_s data_lookup_table[4] __attribute__((section(".bss_ccm")));
+struct neg_drift_comp_s neg_drift_comp[4];
 
 /* copy data from bitmap in flash to calc area */
 void concentration_lookup_table_copy(uint8_t ch)
@@ -38,47 +39,53 @@ void concentration_init(void)
     }
 }
 
+void concentration_neg_drift_compensation_init(uint8_t ch)
+{
+    if (ch >= 4) {
+        return;
+    }
+    neg_drift_comp[ch].drift_update_enable = 1;
+    neg_drift_comp[ch].neg_reading_num = 0;
+    neg_drift_comp[ch].neg_fixed_num = 0;
+    neg_drift_comp[ch].neg_reading_sum = 0;
+    neg_drift_comp[ch].zero_neg_drift = 0;
+    neg_drift_comp[ch].reading_fixed = 0;
+}
+
 int32_t concentration_neg_drift_compensation(uint8_t ch, int32_t reading)
 {
-    static uint8_t drift_update_enable[4] = {1, 1, 1, 1};
-    static uint8_t neg_reading_num[4] = {0, 0, 0, 0};
-    static int32_t neg_reading_sum[4] = {0, 0, 0, 0};
-    static int32_t zero_neg_drift[4] = {0, 0, 0, 0};
-    static int32_t reading_fixed[4] = {0, 0, 0, 0};
-    static uint8_t neg_fixed_num[4] = {0, 0, 0, 0};
-
-    reading_fixed[ch] = reading;
+    neg_drift_comp[ch].reading_fixed = reading;
     
-    if(drift_update_enable[ch]) {
+    if(neg_drift_comp[ch].drift_update_enable) {
         if (reading < 0) {
-            neg_reading_sum[ch] += reading;
-            neg_reading_num[ch] ++;
-            reading_fixed[ch] = 0;
-            if(neg_reading_num[ch] >= 10) {
-                zero_neg_drift[ch] = neg_reading_sum[ch] / neg_reading_num[ch];
-                drift_update_enable[ch] = 0;
-                neg_reading_num[ch] = 0;
-                neg_reading_sum[ch] = 0;
+            neg_drift_comp[ch].neg_reading_sum += reading;
+            neg_drift_comp[ch].neg_reading_num++;
+            neg_drift_comp[ch].reading_fixed = 0;
+            if(neg_drift_comp[ch].neg_reading_num >= 10) {
+                neg_drift_comp[ch].zero_neg_drift = neg_drift_comp[ch].neg_reading_sum / neg_drift_comp[ch].neg_reading_num;
+                neg_drift_comp[ch].drift_update_enable = 0;
+                neg_drift_comp[ch].neg_reading_num = 0;
+                neg_drift_comp[ch].neg_reading_sum = 0;
             }
         } else {
-            neg_reading_num[ch] = 0;
-            neg_reading_sum[ch] = 0;
+            neg_drift_comp[ch].neg_reading_num = 0;
+            neg_drift_comp[ch].neg_reading_sum = 0;
         }
     }
-    if (zero_neg_drift[ch]) {
-        reading_fixed[ch] = reading - zero_neg_drift[ch];
-        if (reading_fixed[ch] < 0) {
-            neg_fixed_num[ch]++;
-            if (neg_fixed_num[ch] >= 10) {
-                drift_update_enable[ch] = 1;
-                neg_fixed_num[ch] = 0;
+    if (neg_drift_comp[ch].zero_neg_drift) {
+        neg_drift_comp[ch].reading_fixed = reading - neg_drift_comp[ch].zero_neg_drift;
+        if (neg_drift_comp[ch].reading_fixed < 0) {
+            neg_drift_comp[ch].neg_fixed_num++;
+            if (neg_drift_comp[ch].neg_fixed_num >= 10) {
+                neg_drift_comp[ch].drift_update_enable = 1;
+                neg_drift_comp[ch].neg_fixed_num = 0;
             }
         } else {
-            neg_fixed_num[ch] = 0;
+            neg_drift_comp[ch].neg_fixed_num = 0;
         }
     }
 
-    return ((reading_fixed[ch] > 0) ? reading_fixed[ch] : 0);
+    return ((neg_drift_comp[ch].reading_fixed > 0) ? neg_drift_comp[ch].reading_fixed : 0);
 }
 
 int32_t concentration_calc(uint8_t ch)
diff --git a/lark1fq/src/concentration.h b/lark1fq/src/concentration.h
index c3c945a..6fb9c4f 100755
--- a/lark1fq/src/concentration.h
+++ b/lark1fq/src/concentration.h
@@ -21,10 +21,20 @@ struct data_lookup_table_s {
     float calc_b[LOOKUP_TABLE_CONCENTRATION_POINTS_MAX];
 };
 
+struct neg_drift_comp_s {
+    uint8_t drift_update_enable;
+    uint8_t neg_reading_num;
+    uint8_t neg_fixed_num;
+    int32_t neg_reading_sum;
+    int32_t zero_neg_drift;
+    int32_t reading_fixed;
+};
+
 extern struct data_lookup_table_s data_lookup_table[4];
 
 void concentration_lookup_table_copy(uint8_t ch);
 void concentration_init(void);
+void concentration_neg_drift_compensation_init(uint8_t ch);
 int32_t concentration_neg_drift_compensation(uint8_t ch, int32_t reading);
 int32_t concentration_calc(uint8_t ch);
 void concentration_loop(void);