diff --git a/PyLog.txt b/PyLog.txt
index ab4945d..26924f0 100644
--- a/PyLog.txt
+++ b/PyLog.txt
@@ -543,3 +543,4 @@
 14/05/2021 15:15:22 FTSampler caught error: int() argument must be a string, a bytes-like object or a number, not 'NoneType'
 17/05/2021 09:51:36 FTSampler caught error: int() argument must be a string, a bytes-like object or a number, not 'NoneType'
 17/05/2021 11:12:38 FTSampler caught error: float() argument must be a string or a number, not 'NoneType'
+21/05/2021 14:59:25 FTSampler caught error: int() argument must be a string, a bytes-like object or a number, not 'NoneType'
diff --git a/sampler/FTSampler.py b/sampler/FTSampler.py
index 7b064de..d3922c8 100644
--- a/sampler/FTSampler.py
+++ b/sampler/FTSampler.py
@@ -65,7 +65,8 @@ redSamPer='SETTINGS:LOG:EXETIME'
 #se non c'è un valore nei campi di redis, popolo il db
 redSrv0.set('SETTINGS:DECIMALS:COUNT',3)
 redSrv0.set('SETTINGS:LOG:STATUS',0)
-
+if redSrv0.get('RTDATA:VALUE:UMEASURE') is None:
+    redSrv0.set('RTDATA:VALUE:UMEASURE', "-")
 if redSrv0.get('SETTINGS:LOG:EXETIME') is None:
     redSrv0.set('SETTINGS:LOG:EXETIME', 1)
 if redSrv0.get('RTDATA:VALUE') is None:
@@ -80,7 +81,6 @@ if redSrv0.get('SETTINGS:SMOOTHING:FUNCTION') is None:
     redSrv0.set('SETTINGS:SMOOTHING:FUNCTION', 0)
 if redSrv0.get('SETTINGS:SMOOTHING:FACTOR') is None:
     redSrv0.set('SETTINGS:SMOOTHING:FACTOR', 10)
-
 if redSrv0.get('SETTINGS:PASSWORD:CURRENT') is None:
     redSrv0.set('SETTINGS:PASSWORD:CURRENT',"-")
 if redSrv0.get('SETTINGS:FOLDER:CURRENT') is None:
@@ -189,8 +189,8 @@ def calculateValue():
     v1 = getRedisVal('RTDATA:OUT:' + ch1)
     v2 = getRedisVal('RTDATA:OUT:' + ch2)
     den = (float(v1)-float(v2))
-    if(den < 0.00001):
-        den = 0.00001
+    if(den < 0.001):
+        den = 0.001
     newValue = float(v2)/float(den)
     redSrv0.set('RTDATA:VALUE',round(newValue,3))
 
diff --git a/server/FTServer.py b/server/FTServer.py
index fcca00e..c5d59f3 100644
--- a/server/FTServer.py
+++ b/server/FTServer.py
@@ -100,6 +100,7 @@ def api_channels_all():
       'Outmin': OUTMIN,
       'Outmax': OUTMAX,
       'UniMeasure' : UNIMISURA,
+      'CalcUMeasure' : getRedisVal('RTDATA:VALUE:UMEASURE'),
       'ChA' : getRedisVal('SETTINGS:CHANNEL:A'),
       'ChB' : getRedisVal('SETTINGS:CHANNEL:B'),
       'ChScaleMax' : getRedisVal('SETTINGS:IN:MAX:'+str(numCh)),
@@ -138,6 +139,7 @@ def api_channels_current():
    #funzione api_channels_all: legge direttamente da redis, ritorna jsonify
    result = {
       'numCh'   : numCh,
+      'CalcUMeasure' : getRedisVal('RTDATA:VALUE:UMEASURE'),
       'SmoothFact' : getRedisVal('SETTINGS:SMOOTHING:FACTOR'),
       'ChanThresh' : getRedisVal('SETTINGS:POWER:THRESH'),
       'timeSrv'   : getRedisVal('RTDATA:TIME:SRV'),
@@ -325,6 +327,12 @@ def setPowerChannel(numPowerCh):
    redSrv0.set('SETTINGS:POWER:CH', numPowerCh)
    return "OK"
 
+@flaskApp.route("/api/v1/setup/calcMeasureUnit", methods=['POST'])
+def VUnitMeasure():
+   CMeasureUnit = request.form['CalcUMeasure']
+   redSrv0.set('RTDATA:VALUE:UMEASURE', CMeasureUnit)
+   return redirect("/settings")
+
 @flaskApp.route("/api/v1/setup/selectProcessing/<processingType>", methods=['PUT'])
 def setProcessing(processingType):
    redSrv0.set('SETTINGS:SMOOTHING:FUNCTION', processingType)
diff --git a/server/templates/logger.html b/server/templates/logger.html
index aafc514..5d3e23e 100644
--- a/server/templates/logger.html
+++ b/server/templates/logger.html
@@ -91,7 +91,7 @@
                 //scarico unità di misura dei canali mostrati
                 $("#UniMisuA").html(result.UniMeasure[result.ChA]);
                 $("#UniMisuB").html(result.UniMeasure[result.ChB]);
-                
+                $("#CalcUMeasure").html(result.CalcUMeasure);
             }});
 
             // A ogni giro di data refresh fix di tabella cartelle e tabella file
@@ -339,14 +339,15 @@
                         </div>
                     </div>
                 </div>
-                    <div class="card text-center">
-                        <div class="card-header">
-                            <strong>Calcolo risultante</strong>
-                        </div>
-                        <div class="card-body">
-                            [Valore B / (Valore A - Valore B)] = &nbsp;<span class="h6" id="ResultValue"></span>
-                        </div>
+                <div class="card text-center">
+                    <div class="card-header">
+                        <strong>Calcolo risultante [Valore B / (Valore A - Valore B)]</strong>
                     </div>
+                    <div class="card-body">
+                        <span class="h3" id="ResultValue"></span> &nbsp;
+                        <span class="h3" id="CalcUMeasure"></span>
+                    </div>
+                </div>
             </div>
             <div class="col-12 col-xl-6">
                 <div class="card my-2">
diff --git a/server/templates/settings.html b/server/templates/settings.html
index 29712e2..e1cf16f 100644
--- a/server/templates/settings.html
+++ b/server/templates/settings.html
@@ -35,6 +35,7 @@
                 $("#UniMisura").val(result.UniMisura);
                 $("#ChanThresh").val(result.ChanThresh);
                 $("#SmoothFact").val(result.SmoothFact);
+                $("#CalcUMeasure").val(result.CalcUMeasure);
                 // inizio nascondendo div2 e div3
                 $("#Div2").hide();
                 $("#Div3").hide();
@@ -346,6 +347,20 @@
                     </form>
                 </div>
             </div>
+            <div class="card my-2 col-12">
+                <div class="row card-header">
+                    <strong>Unità di misura della risultante [Valore B / (Valore A - Valore B)]</strong>
+                </div>
+                <div class="card-body">
+                    <form class="col-12" method="POST" action="/api/v1/setup/calcMeasureUnit">
+                        <div class="row input-group my-2">
+                            <span class="input-group-text col-4">Unità di misura: &nbsp;</span>
+                            <input type="text" class=" form-control col-5" id="CalcUMeasure" name="CalcUMeasure"></input>
+                            <input type="submit" value="SET" class="btn btn-success col-3"></input>
+                        </div>
+                    </form>
+                </div>
+            </div>
             <div class="card my-2 col-12">
                 <div class="row card-header">
                     <strong>Impostazioni canale e soglia per spegnimento</strong>