Fix measurement type string for oxygen in _updateMeasurement method

src/specificClass.js

@@ -322,7 +322,7 @@ class Reactor_PFR extends Reactor {
 
   _updateMeasurement(measurementType, value, position, context) {
     switch(measurementType) {
-      case "Quantity (oxygen)":
+      case "quantity (oxygen)":
         grid_pos = Math.round(position / this.config.length * this.n_x);
         this.state[grid_pos][S_O_INDEX] = value; // naive approach for reconciling measurements and simulation
         break;