diff --git a/app/build.gradle b/app/build.gradle
index 55ec74c..4fae05b 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -14,12 +14,13 @@ android {
     compileSdk 34
     namespace 'in.sminnovations.hpostesting'
 
+    // prod - production, preprod - preproduction, quality - qc,
     defaultConfig {
         applicationId "in.sminnovations.hpostesting"
         minSdk 21
         targetSdk 34
-        versionCode 24
-        versionName "2.1.24"
+        versionCode 28
+        versionName "2.1.28"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
diff --git a/app/src/main/java/com/example/hpostesting/data/constant/Constants.kt b/app/src/main/java/com/example/hpostesting/data/constant/Constants.kt
index bcef509..33aff22 100644
--- a/app/src/main/java/com/example/hpostesting/data/constant/Constants.kt
+++ b/app/src/main/java/com/example/hpostesting/data/constant/Constants.kt
@@ -74,4 +74,7 @@ object Constants {
     const val BUFFER_VALUE_3 = "BufferValue3"
     const val BUFFER_VALUE_4 = "BufferValue4"
     const val DEVICE_ID = "DEVICE_ID"
+
+    const val BUFFER_LED_LOWER_BOUND = 20000
+    const val BUFFER_LED_HIGHER_BOUND = 24000
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/example/hpostesting/presentation/hemocube/HemoCubeFragment.kt b/app/src/main/java/com/example/hpostesting/presentation/hemocube/HemoCubeFragment.kt
index 46bd65c..735fcc6 100644
--- a/app/src/main/java/com/example/hpostesting/presentation/hemocube/HemoCubeFragment.kt
+++ b/app/src/main/java/com/example/hpostesting/presentation/hemocube/HemoCubeFragment.kt
@@ -45,12 +45,13 @@ class HemoCubeFragment : Fragment() {
     private val testingTrace = Firebase.performance.newTrace("testing_trace")
     private var led1BufferForDevice = 0.0
     private var led2BufferForDevice = 0.0
-    private var led3BufferForDevice =  0.0
+    private var led3BufferForDevice = 0.0
     private var led4BufferForDevice = 0.0
     private var led1SampleForDevice = 0.0
     private var led2SampleForDevice = 0.0
-    private var led3SampleForDevice =  0.0
+    private var led3SampleForDevice = 0.0
     private var led4SampleForDevice = 0.0
+    private var validationError = false
 
     override fun onCreateView(
         inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?,
@@ -84,8 +85,8 @@ class HemoCubeFragment : Fragment() {
         binding.nameEditText.visibility = View.GONE
         binding.tvTitle.visibility = View.GONE
         binding.btnGo.visibility = View.GONE
-        binding.btnSubmit.isEnabled = true
-        binding.btnSubmit.isClickable = true
+        binding.btnSubmit.isEnabled = false
+        binding.btnSubmit.isClickable = false
         binding.btnPlacebuffer.visibility = View.GONE
 
         binding.tvName.text = "Name: ${testDetails?.name}\n ID: ${testDetails?._id}"
@@ -96,8 +97,8 @@ class HemoCubeFragment : Fragment() {
                 binding.tvSubtitle4.visibility = View.VISIBLE
                 binding.tvSubtitle4.text = "Sample Started"
             }
-                startSampleProcess()
-                it.visibility = View.GONE
+            startSampleProcess()
+            it.visibility = View.GONE
         }
 
         binding.btnPlacebuffer.setOnClickListener {
@@ -106,10 +107,13 @@ class HemoCubeFragment : Fragment() {
             } else {
                 activity?.runOnUiThread {
                     binding.tvSubtitle4.visibility = View.VISIBLE
+//                    binding.tvSubtitle4.text = "Buffer Started"
                 }
+
                 checkAndStartProcess()
+                it.visibility = View.GONE
             }
-            it.visibility = View.GONE
+
         }
 
     }
@@ -352,7 +356,8 @@ class HemoCubeFragment : Fragment() {
                 sampleIntensity = resultLines[7].split(' ')[1].trim()
                 led3SampleForDevice = resultLines[7].split(' ')[1].trim().toDoubleOrNull()!!
                 sampleIntensity = resultLines[8].split(' ')[1].split('\r')[0].trim()
-                led4SampleForDevice = resultLines[8].split(' ')[1].split('\r')[0].trim().toDoubleOrNull()!!
+                led4SampleForDevice =
+                    resultLines[8].split(' ')[1].split('\r')[0].trim().toDoubleOrNull()!!
                 processResult()
             }
         }
@@ -389,6 +394,7 @@ class HemoCubeFragment : Fragment() {
 
     private fun processResult() {
         try {
+            hemoCubeViewModel.messages.postValue("processing result")
             val deviceLog = resultData
 
             val pInfo = requireActivity().packageManager.getPackageInfo(
@@ -400,11 +406,36 @@ class HemoCubeFragment : Fragment() {
             val led2Average = log10(led2BufferForDevice?.div(led2SampleForDevice!!) ?: 0.0)
             val led3Average = log10(led3BufferForDevice?.div(led3SampleForDevice!!) ?: 0.0)
             val led4Average = log10(led4BufferForDevice?.div(led4SampleForDevice!!) ?: 0.0)
-            val deviceRatio = led1Average / led3Average
+            val deviceRatio = led3Average / led1Average
 
-            if (led1Average < 0 || led2Average < 0) {
+            if (led1Average < 0 || led2Average < 0 || led3Average < 0 || led4Average < 0) {
+                validationError = true
                 activity?.runOnUiThread {
-                    binding.errorMessage.text = "Warning: Negative Abs. Retake Blank Reading"
+                    binding.errorMessage.text = "Error: Negative Abs. Retake Blank Reading"
+                    binding.errorMessage.visibility = View.VISIBLE
+                }
+            }
+
+            if (led1BufferForDevice < Constants.BUFFER_LED_LOWER_BOUND
+                || led2BufferForDevice < Constants.BUFFER_LED_LOWER_BOUND
+                || led3BufferForDevice < Constants.BUFFER_LED_LOWER_BOUND
+                || led4BufferForDevice < Constants.BUFFER_LED_LOWER_BOUND
+            ) {
+                validationError = true
+                activity?.runOnUiThread {
+                    binding.errorMessage.text = "Error: Invalid Test. Blank reading is too low"
+                    binding.errorMessage.visibility = View.VISIBLE
+                }
+            }
+
+            if (led1BufferForDevice > Constants.BUFFER_LED_HIGHER_BOUND
+                || led2BufferForDevice > Constants.BUFFER_LED_HIGHER_BOUND
+                || led3BufferForDevice > Constants.BUFFER_LED_HIGHER_BOUND
+                || led4BufferForDevice > Constants.BUFFER_LED_HIGHER_BOUND
+            ) {
+                validationError = true
+                activity?.runOnUiThread {
+                    binding.errorMessage.text = "Error: Invalid Test. Blank reading is too high"
                     binding.errorMessage.visibility = View.VISIBLE
                 }
             }
@@ -440,12 +471,14 @@ class HemoCubeFragment : Fragment() {
                         apply()
                     }
                 }
+                if (!validationError) {
                     activity?.runOnUiThread {
                         binding.btnSubmit.visibility = View.VISIBLE
+                        binding.btnSubmit.isEnabled = true
+                        binding.btnSubmit.isClickable = true
+                        binding.clParent.setBackgroundColor(Color.parseColor("#edfffd"))
                     }
-                    binding.btnSubmit.isEnabled = true
-                    binding.btnSubmit.isClickable = true
-                    binding.clParent.setBackgroundColor(Color.parseColor("#edfffd"))
+                }
             }
         } catch (e: Exception) {
             Toast.makeText(
@@ -459,6 +492,7 @@ class HemoCubeFragment : Fragment() {
 
     private fun findResult(calculatedRatio: Double?): String {
         try {
+            hemoCubeViewModel.messages.postValue("result classification")
             if (calculatedRatio != null) {
                 if (calculatedRatio < 0.05)
                     return "Inconclusive. Very low Absorbance - Repeat test with Higher Blood Volume"
@@ -475,14 +509,14 @@ class HemoCubeFragment : Fragment() {
                 if (calculatedRatio > 0.35)
                     return "Inconclusive. Repeat with test with lower volume of blood"
             } else {
-                return "NULL"
+                return "INVALID"
             }
         } catch (e: Exception) {
             showToast("error while performing classification")
             Firebase.crashlytics.recordException(e)
             return "ERROR"
         }
-        return "NULL"
+        return "INVALID"
     }
 
     private fun showToast(message: String) {