diff --git a/src/widgets/plotwidget.h b/src/widgets/plotwidget.h
--- a/src/widgets/plotwidget.h
+++ b/src/widgets/plotwidget.h
@@ -66,7 +66,7 @@
      * @brief set The Maximum Number of points per series the plot widget stores
      * @param newMax: new maximum Number (default:120)
      */
-    void setMaximumPoints(const uint newMax);
+    void setMaximumPoints(const int newMax);
 
     /**
      * @brief set the maximum temperature shown on the plot
diff --git a/src/widgets/plotwidget.cpp b/src/widgets/plotwidget.cpp
--- a/src/widgets/plotwidget.cpp
+++ b/src/widgets/plotwidget.cpp
@@ -84,9 +84,9 @@
     return _plots.keys();
 }
 
-void PlotWidget::setMaximumPoints(const uint newMax)
+void PlotWidget::setMaximumPoints(const int newMax)
 {
-    m_maximumPoints = newMax;
+    m_maximumPoints = std::max(newMax, 0);
 }
 
 void PlotWidget::setMaximumTemperature(const uint maxTemp)
diff --git a/testclient/main.cpp b/testclient/main.cpp
--- a/testclient/main.cpp
+++ b/testclient/main.cpp
@@ -30,7 +30,7 @@
 
     QCoreApplication::setOrganizationName(QStringLiteral("KDE"));
     QCoreApplication::setOrganizationDomain(QStringLiteral("kde.org"));
-    QCoreApplication::setApplicationName(QStringLiteral("AtCore - KDE Print Service"));
+    QCoreApplication::setApplicationName(QStringLiteral("AtCore - Test Client"));
 
     MainWindow window;
     window.show();
diff --git a/testclient/mainwindow.h b/testclient/mainwindow.h
--- a/testclient/mainwindow.h
+++ b/testclient/mainwindow.h
@@ -53,7 +53,7 @@
      * @param  number     : index of sensor
      * @param  temp       : temperature
      */
-    void checkTemperature(uint sensorType, uint number, uint temp);
+    void checkTemperature(uint sensorType, uint number, float temp);
 
 private slots:
     //ButtonEvents
diff --git a/testclient/mainwindow.cpp b/testclient/mainwindow.cpp
--- a/testclient/mainwindow.cpp
+++ b/testclient/mainwindow.cpp
@@ -154,11 +154,13 @@
     connect(printWidget, &PrintWidget::fanSpeedChanged, core, &AtCore::setFanSpeed);
 
     connect(printWidget, &PrintWidget::printSpeedChanged, this, [this](const int speed) {
-        core->setPrinterSpeed(speed);
+        std::max(1, speed);
+        core->setPrinterSpeed(uint(speed));
     });
 
     connect(printWidget, &PrintWidget::flowRateChanged, [this](const int rate) {
-        core->setFlowRate(rate);
+        std::max(1, rate);
+        core->setFlowRate(uint(rate));
     });
 
     printDock = new QDockWidget(tr("Print"), this);
@@ -370,7 +372,7 @@
 
 }
 
-void MainWindow::checkTemperature(uint sensorType, uint number, uint temp)
+void MainWindow::checkTemperature(uint sensorType, uint number, float temp)
 {
     QString msg;
     switch (sensorType) {
@@ -400,7 +402,7 @@
     }
 
     msg.append(QString::fromLatin1("[%1] : %2").arg(
-                   QString::number(number), QString::number(temp)
+                   QString::number(number), QString::number(double(temp), 'f', 2)
                ));
 
     logWidget->appendLog(msg);