diff --git a/src/groupcontrol.test.js b/src/groupcontrol.test.js
index ee14089..796876d 100644
--- a/src/groupcontrol.test.js
+++ b/src/groupcontrol.test.js
@@ -270,9 +270,6 @@ async function testNormalizedScaling(mg, pt1) {
     console.log("\n🧪 testing normalized scaling (0-100%)...");
     mg.setScaling("normalized");
 
-    //first set pressure:
-    pt1.inputValue = 1400;
-
     //fetch ranges
     const maxflow = mg.dynamicTotals.flow.max;
     console.log(`max group flow capacity: ${maxflow.toFixed(2)} m3/h`);
@@ -280,20 +277,47 @@ async function testNormalizedScaling(mg, pt1) {
     console.log(`min group flow capacity: ${minFlow.toFixed(2)} m3/h`);
         
     const testPoints = [0, 10, 25, 50, 75, 90, 100];
+    const testPressurePoints = [800, 1200, 1600, 2000];
     
-    for (const demand of testPoints) {
+    for (const pressure of testPressurePoints) {
         try {
-            console.log(`\n--- normalized demand: ${demand}% ---`);
-            await mg.handleInput("parent", demand);
-            
-            
-            logMachineStates(mg, `normalized ${demand}%`);
-            
-        } catch (err) {
-            console.error(`❌ error at ${demand}%:`, err.message);
+            console.log(`\n--- testing at ${pressure} mbar ---`);
+            pt1.calculateInput(pressure);
+            logMachineStates(mg, `${pressure} mbar, before demand tests`);
+
+
+        for (const demand of testPoints) {
+            try {
+                console.log(`\n--- normalized demand: ${demand}% ---`);
+                await mg.handleInput("parent", demand);
+                
+                
+                logMachineStates(mg, `normalized ${demand}%`);
+
+                //check if total flow is within expected range
+                const totalFlow = mg.measurements?.type("flow")?.variant("predicted")?.position("downstream")?.getCurrentValue() || 0;
+                const expectedFlow = minFlow + (demand / 100) * (maxflow - minFlow);
+                const percentTolerance = 0.1 ; // % tolerance of expected flow
+                const tolerance = (expectedFlow * percentTolerance) / 100;
+
+                if (totalFlow < expectedFlow - tolerance || totalFlow > expectedFlow + tolerance) {
+                    console.warn(`⚠️ Total flow (${totalFlow.toFixed(2)} m3/h) is outside expected range (${(expectedFlow - tolerance).toFixed(2)} - ${(expectedFlow + tolerance).toFixed(2)} m3/h)`);
+                }
+                else {
+                    console.log( `Difference between expected and actual flow: ${(totalFlow - expectedFlow).toFixed(2)} m3/h`);
+                    console.log(`✅ Total flow (${totalFlow.toFixed(2)} m3/h) is within expected range (${(expectedFlow - tolerance).toFixed(2)} - ${(expectedFlow + tolerance).toFixed(2)} m3/h)`);
+                }
+
+            } catch (err) {
+                console.error(`❌ error at ${demand}%:`, err.message);
+            }
         }
+        
+    } catch (err) {
+        console.error(`❌ error setting pressure to ${pressure}:`, err.message);
     }
 }
+}
 
 async function testAbsoluteScaling(mg, pt1) {
     console.log("\n🧪 testing absolute scaling...");
diff --git a/src/specificClass.js b/src/specificClass.js
index 30402b9..3d0c017 100644
--- a/src/specificClass.js
+++ b/src/specificClass.js
@@ -63,17 +63,21 @@ class MachineGroup {
        if(softwareType == "machine"){
            // Check if the machine is already registered
            this.machines[child.config.general.id] === undefined ?  this.machines[child.config.general.id] = child : this.logger.warn(`Machine ${child.config.general.id} is already registered.`);
-           this.handleChildChange();
-           /*
-            // Listen for changes in the child machine
-            child.emitter.on('stateChange', () => this.handleChildChange());
-            child.emitter.on('pressureChange', () => this.handlePressureChange());
-            child.emitter.on('ncogChange', () => this.handleChildChange());
-            */
+           
+           //listen for machine pressure changes
+           this.logger.debug(`Listening for pressure changes from machine ${child.config.general.id}`);
+
+
+           child.measurements.emitter.on("pressure.measured.differential", (eventData) => {
+               this.logger.debug(`Pressure update from ${child.config.general.id}: ${eventData.value} ${eventData.unit}`);
+               this.handleChildChange();
+           });
 
        }
     }
 
+    
+
     calcAbsoluteTotals() {
 
         const absoluteTotals = { flow: { min: Infinity, max: 0 }, power: { min: Infinity, max: 0 } };
@@ -112,7 +116,10 @@ class MachineGroup {
 
         const dynamicTotals = { flow: { min: Infinity, max: 0 }, power: { min: Infinity, max: 0 }, NCog : 0 };
 
+        this.logger.debug(`\n --------- Calculating dynamic totals for ${Object.keys(this.machines).length} machines. @ current pressure settings : ----------`);
         Object.values(this.machines).forEach(machine => {
+            this.logger.debug(`Processing machine with id: ${machine.config.general.id}`);
+            this.logger.debug(`Current pressure settings: ${JSON.stringify(machine.predictFlow.currentF)}`);
             //fetch min flow ever seen over all machines
             const minFlow = machine.predictFlow.currentFxyYMin; 
             const maxFlow = machine.predictFlow.currentFxyYMax;