diff --git a/+DataKit/+Metadata/@sparseBitmask/setBit.m b/+DataKit/+Metadata/@sparseBitmask/setBit.m
index 3fdc26d..4a67c15 100644
--- a/+DataKit/+Metadata/@sparseBitmask/setBit.m
+++ b/+DataKit/+Metadata/@sparseBitmask/setBit.m
@@ -1,4 +1,4 @@
-function obj = setBit(obj,i,j,bit,highlow)
+function obj = setBit(obj,i,j,bit,highlow,varargin)
 
 % Note:
 % if the same bit at the same index is adressed multiple times with
@@ -17,6 +17,17 @@
 
     import DataKit.arrayhom
     
+    if nargin == 5
+        fastMode = true;
+    elseif nargin == 6
+        fastMode = varargin{1};
+        if ~isscalar(fastMode) || ~islogical(fastMode)
+            error('Dingi:DataKit:Metadata:sparseBitmask:setBit:invalidFastModeInput',...
+            'FastMode has to be provided as a scalar logical.')
+        end
+    end
+    
+    
     if any(bit(:) > 52) || any(bit(:) < 1)
         error('Dingi:DataKit:Metadata:sparseBitmask:setBit:bitPositionExceedsLimit',...
             'A bit position exceeds the limits. Only bits 1 to 52 can be set.')
@@ -48,13 +59,37 @@
     highlow(highlow > 0) = 1;
     
     [i,j,bit,highlow] = arrayhom(i,j,bit,highlow);
+    
+    if ~fastMode
+        [u,uind] = unique(cat(2,i,j,bit),'rows');
+
+        i           = u(:,1);
+        j           = u(:,2);
+        bit      	= u(:,3);
+        highlow     = highlow(uind);
+    end
+    
     if nnz(obj.Bitmask) == 0
         % no non-zero elements
         bitmaskNew 	= bitset(zeros(size(bit)),bit,highlow);
         obj.Bitmask	= sparse(i,j,bitmaskNew,Sz(1),Sz(2));
     else
-        
         % non-zero elements already exist
+        
+        %%{
+        ind             = sub2ind(obj.Sz,i,j);
+        bitmaskIn       = full(obj.Bitmask(ind));
+        
+        if ~fastMode
+            [uInd,~,uIndInd2]   = unique(ind);
+            bitmaskIn         	= bitset(bitmaskIn,bit,highlow);
+            bitmaskOut      	= accumarray(uIndInd2,bitmaskIn,size(uInd),@sum);
+            obj.Bitmask(uInd)   = bitmaskOut;
+        else
+            obj.Bitmask(ind)  	= bitset(bitmaskIn,bit,highlow);
+        end
+        %}
+        %{
         [iBm,jBm]           = find(obj.Bitmask);
         indBm               = sub2ind(obj.Sz,iBm,jBm);
         
@@ -86,6 +121,7 @@
         bitmask(indChange)      = bitmaskChange;
         
         obj.Bitmask             = bitmask;
+        %}
     end
     
 %     for ii = 1:n
diff --git a/+DataKit/+Metadata/@sparseBitmask/sparseBitmask.m b/+DataKit/+Metadata/@sparseBitmask/sparseBitmask.m
index c2a4f65..ca56b4a 100644
--- a/+DataKit/+Metadata/@sparseBitmask/sparseBitmask.m
+++ b/+DataKit/+Metadata/@sparseBitmask/sparseBitmask.m
@@ -128,7 +128,7 @@
     methods
         disp(obj)
         obj = initializeBitmask(obj,i,j,bit,sz)
-        obj = setBit(obj,i,j,bit,highlow)
+        obj = setBit(obj,i,j,bit,highlow,varargin)
         varargout = getBit(obj,varargin)
     end
     methods (Static, Hidden)
diff --git a/+DataKit/@dataPool/applyCalibrationFunction.m b/+DataKit/@dataPool/applyCalibrationFunction.m
index d2e1a83..8ce1866 100644
--- a/+DataKit/@dataPool/applyCalibrationFunction.m
+++ b/+DataKit/@dataPool/applyCalibrationFunction.m
@@ -70,6 +70,8 @@
 
     obj.Data{poolIdx}(:,variableIdx)	= fh(time,obj.DataRaw{poolIdx}(:,variableIdx));
     
+    obj.IndexNeedsUpdating = true;
+    
     if nargout == 1
         varargout{1} = obj;
     end
diff --git a/+DataKit/@dataPool/setInfoProperty.m b/+DataKit/@dataPool/setInfoProperty.m
index c74b10a..cde2f26 100644
--- a/+DataKit/@dataPool/setInfoProperty.m
+++ b/+DataKit/@dataPool/setInfoProperty.m
@@ -10,6 +10,8 @@
     
     obj.Info(pool).(property)(idx) = value;
     
+    obj.IndexNeedsUpdating = true;
+    
     if nargout == 1
         varargout{1} = obj;
     end
diff --git a/+DataKit/@dataPool/setMeasuringDeviceProperty.m b/+DataKit/@dataPool/setMeasuringDeviceProperty.m
index daa3c35..6f06ecc 100644
--- a/+DataKit/@dataPool/setMeasuringDeviceProperty.m
+++ b/+DataKit/@dataPool/setMeasuringDeviceProperty.m
@@ -19,6 +19,8 @@
     
     obj.Info(pool).VariableMeasuringDevice(idx).(property) = value;
     
+    obj.IndexNeedsUpdating = true;
+    
     if nargout == 1
         varargout{1} = obj;
     end
diff --git a/+GearKit/@gearDeployment/calibrateMeasuringDevices.m b/+GearKit/@gearDeployment/calibrateMeasuringDevices.m
index a699142..5ef33a0 100644
--- a/+GearKit/@gearDeployment/calibrateMeasuringDevices.m
+++ b/+GearKit/@gearDeployment/calibrateMeasuringDevices.m
@@ -135,6 +135,6 @@ function calibrateMeasuringDevices(obj)
             obj.data.setInfoProperty(pool(v),var(v),'Variable',valueVariableInfo.Variable);
         end
     end
-
+    
     printDebugMessage('Info','Calibrating %s measuring device(s)... done',char(obj.gearType))
 end
diff --git a/+Tests/+DataKit/+Metadata/+sparseBitmask/setBit_test.m b/+Tests/+DataKit/+Metadata/+sparseBitmask/setBit_test.m
index 54694f1..ab70aef 100644
--- a/+Tests/+DataKit/+Metadata/+sparseBitmask/setBit_test.m
+++ b/+Tests/+DataKit/+Metadata/+sparseBitmask/setBit_test.m
@@ -121,7 +121,7 @@ function testIndexExceedsSize(testCase)
 %                 setBit(testCase.Bitmask,testCase.Sz(1) + 1,1,1,1),...
 %                 'Dingi:DataKit:Metadata:sparseBitmask:setBit:subscriptsExceedBitmaskSize')
         end
-        function testSetBit(testCase,i,j,bit,hl)
+        function testSetBitFastModeDisabled(testCase,i,j,bit,hl)
             import matlab.unittest.fixtures.SuppressedWarningsFixture
             import DataKit.Metadata.sparseBitmask
             import DataKit.arrayhom
@@ -147,7 +147,7 @@ function testSetBit(testCase,i,j,bit,hl)
             
             % get actual value
             BitmaskA	= testCase.Bitmask;
-            act         = setBit(BitmaskA,i,j,bit,hl);
+            act         = setBit(BitmaskA,i,j,bit,hl,false); % test without fastMode
             act       	= act.Bitmask;
             
             % determine expected bitmask
@@ -159,7 +159,9 @@ function testSetBit(testCase,i,j,bit,hl)
             [uBits,~,uBitsInd]  = unique(cat(2,ind,bit2),'rows'); % get unique index-bit touples
             for ii = 1:size(uBits,1)
                 mask                = uBitsInd == ii;
-                highlow             = max(hl2(mask));   % if the same bit is addressed multiple times set it to the max of the corresponding highlow values.
+                highlow             = hl2(find(mask,1));   % if the same bit is addressed multiple times set it to the first of the corresponding highlow values.
+%                 highlow             = max(hl2(mask));   % if the same bit is addressed multiple times set it to the first of the corresponding highlow values.
+
                 exp(uBits(ii,1))	= bitset(full(exp(uBits(ii,1))),uBits(ii,2),highlow);
             end