diff --git a/src/main/java/com/whdc/zhdbaqapi/service/impl/DeviceDataServiceImpl.java b/src/main/java/com/whdc/zhdbaqapi/service/impl/DeviceDataServiceImpl.java
index 86edcac..013cba0 100644
--- a/src/main/java/com/whdc/zhdbaqapi/service/impl/DeviceDataServiceImpl.java
+++ b/src/main/java/com/whdc/zhdbaqapi/service/impl/DeviceDataServiceImpl.java
@@ -104,7 +104,7 @@ public class DeviceDataServiceImpl extends ServiceImpl<DeviceDataMapper, DeviceD
             Calendar c        = Calendar.getInstance();
 
             if (lasttm == null) {
-                c.add(Calendar.DATE, -31);
+                c.add(Calendar.DATE, -31); // 取近 31 天的数据
             } else {
                 c.setTime(lasttm);
                 c.add(Calendar.SECOND, 1); // 传最后数据时间，会一直拉到最后一条记录，所以这里加了一秒
@@ -142,11 +142,13 @@ public class DeviceDataServiceImpl extends ServiceImpl<DeviceDataMapper, DeviceD
                         log.debug("参数数据不完整");
                     } else {
                         // 计算公式  压力（P，单位 kPa） = G (R1 - R0) + K(T1 - T0)
-
-                        R0 = DataUtils.sqrt(R0.multiply(BigDecimal.valueOf(1000)), 6);
+                        // 2022-08-03 R 是模数，模数 = 频率的平方 / 1000
 
                         BigDecimal T1      = record.getDataB();
                         BigDecimal R1      = record.getDataA();
+
+                        R1 = R1.multiply(R1).divide(BigDecimal.valueOf(1000), 6, BigDecimal.ROUND_HALF_UP);
+
                         BigDecimal R3      = R1.subtract(R0);
                         BigDecimal T3      = T1.subtract(T0);
                         BigDecimal GR      = G.multiply(R3);