diff --git a/src/MNH/read_field.f90 b/src/MNH/read_field.f90
index 0264f75c62e7c809dc1f7ff498442ed43be22d14..4f40512544ce67621915080d64b8d49cf89b1945 100644
--- a/src/MNH/read_field.f90
+++ b/src/MNH/read_field.f90
@@ -1241,7 +1241,7 @@ END IF
 !
 IF (NSV_LNOXEND>=NSV_LNOXBEG) THEN
   TZFIELD%CSTDNAME   = ''
-  TZFIELD%CUNITS     = 'ppv'
+  TZFIELD%CUNITS     = 'ppb'
   TZFIELD%CDIR       = 'XY'
   TZFIELD%NGRID      = 1
   TZFIELD%NTYPE      = TYPEREAL
diff --git a/src/MNH/write_lfifm1_for_diag.f90 b/src/MNH/write_lfifm1_for_diag.f90
index e94351e1e9c7117b0c95218d7b1d9d30b6964b8f..4adbf49c02ee35e6434e867588feb0b5993deddf 100644
--- a/src/MNH/write_lfifm1_for_diag.f90
+++ b/src/MNH/write_lfifm1_for_diag.f90
@@ -1,4 +1,4 @@
-!MNH_LIC Copyright 1994-2021 CNRS, Meteo-France and Universite Paul Sabatier
+!MNH_LIC Copyright 1994-2022 CNRS, Meteo-France and Universite Paul Sabatier
 !MNH_LIC This is part of the Meso-NH software governed by the CeCILL-C licence
 !MNH_LIC version 1. See LICENSE, CeCILL-C_V1-en.txt and CeCILL-C_V1-fr.txt
 !MNH_LIC for details. version 1.
@@ -1242,7 +1242,7 @@ IF (LCHEMDIAG) THEN
     TZFIELD%CMNHNAME   = TRIM(UPCASE(CNAMES(JSV-NSV_CHGSBEG+1)))//'T'
     TZFIELD%CSTDNAME   = ''
     TZFIELD%CLONGNAME  = TRIM(TZFIELD%CMNHNAME)
-    TZFIELD%CUNITS     = 'ppbv'
+    TZFIELD%CUNITS     = 'ppb'
     TZFIELD%CDIR       = 'XY'
     WRITE(TZFIELD%CCOMMENT,'(A6,A4,I3.3)')'X_Y_Z_','CHIM',JSV
     TZFIELD%NGRID      = 1
@@ -1511,7 +1511,7 @@ IF (.NOT.(LUSECHEM .OR. LCHEMDIAG) .AND. LCH_CONV_LINOX) THEN
     TZFIELD%CMNHNAME   = 'LINOXT'
     TZFIELD%CSTDNAME   = ''
     TZFIELD%CLONGNAME  = TRIM(TZFIELD%CMNHNAME)
-    TZFIELD%CUNITS     = 'ppbv'
+    TZFIELD%CUNITS     = 'ppb'
     TZFIELD%CDIR       = 'XY'
     WRITE(TZFIELD%CCOMMENT,'(A6,A4,I3.3)')'X_Y_Z_','LNOX',JSV
     TZFIELD%NGRID      = 1
@@ -1554,7 +1554,7 @@ IF (LSALT) THEN
   !
   TZFIELD%CSTDNAME   = ''
   TZFIELD%CDIR       = 'XY'
-  TZFIELD%CUNITS     = 'ppbv'
+  TZFIELD%CUNITS     = 'ppb'
   TZFIELD%NGRID      = 1
   TZFIELD%NTYPE      = TYPEREAL
   TZFIELD%NDIMS      = 3
@@ -1639,7 +1639,7 @@ IF (LSALT.AND.LDEPOS_SLT(IMI)) THEN
   ZSSLTDEP=XSVT(:,:,:,NSV_SLTDEPBEG:NSV_SLTDEPEND)
   !
   TZFIELD%CSTDNAME   = ''
-  TZFIELD%CUNITS     = 'ppbv'
+  TZFIELD%CUNITS     = 'ppb'
   TZFIELD%CDIR       = 'XY'
   TZFIELD%NGRID      = 1
   TZFIELD%NTYPE      = TYPEREAL
@@ -1739,7 +1739,7 @@ IF (LDUST) THEN
     ALLOCATE(ZN0_DST(SIZE(XSVT,1), SIZE(XSVT,2), SIZE(XSVT,3), NMODE_DST))
   !
   TZFIELD%CSTDNAME   = ''
-  TZFIELD%CUNITS     = 'ppbv'
+  TZFIELD%CUNITS     = 'ppb'
   TZFIELD%CDIR       = 'XY'
   TZFIELD%NGRID      = 1
   TZFIELD%NTYPE      = TYPEREAL
@@ -1817,7 +1817,7 @@ IF (LDUST.AND.LDEPOS_DST(IMI)) THEN
   ZSDSTDEP=XSVT(:,:,:,NSV_DSTDEPBEG:NSV_DSTDEPEND)
   !
   TZFIELD%CSTDNAME   = ''
-  TZFIELD%CUNITS     = 'ppbv'
+  TZFIELD%CUNITS     = 'ppb'
   TZFIELD%CDIR       = 'XY'
   TZFIELD%NGRID      = 1
   TZFIELD%NTYPE      = TYPEREAL
@@ -1910,7 +1910,7 @@ END IF
 ! Aerosol
 IF ((LCHEMDIAG).AND.(LORILAM).AND.(LUSECHEM)) THEN
   TZFIELD%CSTDNAME   = ''
-  TZFIELD%CUNITS     = 'ppbv'
+  TZFIELD%CUNITS     = 'ppb'
   TZFIELD%CDIR       = 'XY'
   TZFIELD%NGRID      = 1
   TZFIELD%NTYPE      = TYPEREAL