diff --git a/notebooks/demo_acsm_pipeline.ipynb b/notebooks/demo_acsm_pipeline.ipynb
index 54945c5..cb7959e 100644
--- a/notebooks/demo_acsm_pipeline.ipynb
+++ b/notebooks/demo_acsm_pipeline.ipynb
@@ -151,7 +151,9 @@
     "#command = ['python', 'pipelines/steps/compute_automated_flags.py', path_to_data_file, dataset_name, path_to_config_file]\n",
     "#status = subprocess.run(command, capture_output=True, check=True)\n",
     "#print(status.stdout.decode())\n",
-    "generate_flags(path_to_data_file, 'diagnostics')\n"
+    "generate_flags(path_to_data_file, 'diagnostics')\n",
+    "\n",
+    "generate_flags(path_to_data_file, 'cpc')\n"
    ]
   },
   {
diff --git a/pipelines/steps/generate_flags.py b/pipelines/steps/generate_flags.py
index 3751601..81b8c79 100644
--- a/pipelines/steps/generate_flags.py
+++ b/pipelines/steps/generate_flags.py
@@ -28,12 +28,28 @@ import dima.src.hdf5_ops as dataOps
 import pipelines.steps.utils as stepUtils
 import dima.utils.g5505_utils as utils
 import json
-from pipelines.steps.utils import load_project_yaml_files
+from pipelines.steps.utils import load_project_yaml_files, get_metadata
+from math import floor
 
-def compute_cpc_flags():
-    # TODO: ask rob where to find this information.
+def generate_cpc_flags(data_table, datetime_var: str = 'start_time'):
+    # TODO: ask Rob where to find this information.
+    required_variables = ['start_time', 'end_time', 'st_y', 'ed_y', 'p_int', 'T_int', 'conc', 'numflag']
+
+    # Optionally check if required variables exist in data_table
+    # Uncomment if you want to enforce the check:
+    # if not all(var in data_table.columns for var in required_variables):
+    #     raise ValueError("Some required variables are missing from the data_table.")
+
+    # Select only datetime and numflag columns
+    flags_table = data_table.loc[:, [datetime_var, 'numflag']].copy()
+    print(flags_table.head())
+
+    # Multiply numflag by 100 and floor it
+    flags_table['numflag'] = flags_table['numflag'].apply(lambda x: int(floor(x * 1000)))
+    flags_table.rename(columns={'numflag':'numflag_cpc'}, inplace=True)
+
+    return flags_table
 
-    return 0
 
 #def compute_diagnostic_variable_flags(data_table, validity_thresholds_dict):
 def generate_diagnostic_flags(data_table, validity_thresholds_dict):
@@ -101,6 +117,7 @@ def generate_diagnostic_flags(data_table, validity_thresholds_dict):
     #)
     return new_data_table
 
+from scipy.interpolate import interp1d
 
 def generate_species_flags(data_table : pd.DataFrame, calib_param_dict : dict, flagsFolderPath, datetime_var : str = 't_start_Buf'):
 
@@ -124,29 +141,79 @@ def generate_species_flags(data_table : pd.DataFrame, calib_param_dict : dict, f
     #print(manual_json_flags,csv_flags)
 
     if csv_flags:
-        flags_table = pd.read_csv(os.path.join(flagsFolderPath, csv_flags[0]))
-        if 'numflag_any_diagnostic_flag' in flags_table.columns:
 
-            # Define condition for renaming
-            required = lambda var: var != datetime_var and var in predefined_species
+        # Loop over CSV files in the flags folder
+        for filename in csv_flags:
+            filePath = os.path.join(flagsFolderPath, filename)
+            fileMetadataDict = get_metadata(filePath)
+            flag_datetime_var = fileMetadataDict['datetime_var']
 
-            # Create renaming map using dictionary comprehension
-            renaming_map = {var: f'numflag_{var}' for var in data_table.columns if required(var)}
+            flags_table = pd.read_csv(filePath)
+
+            # Ensure datetime type
+            data_table[datetime_var] = pd.to_datetime(data_table[datetime_var])
+            flags_table[flag_datetime_var] = pd.to_datetime(flags_table[flag_datetime_var])
+
+            if 'numflag_any_diagnostic_flag' in flags_table.columns:
+                # Sort for interpolation
+                flags_table_sorted = flags_table.sort_values(flag_datetime_var)
+
+                # Pre-convert datetimes to int64 for interpolation
+                flag_times_int = flags_table_sorted[flag_datetime_var].astype(np.int64)
+                data_times_int = data_table[datetime_var].astype(np.int64)
+
+                # Nearest-neighbor interpolator
+                flag_interp_func = interp1d(
+                    flag_times_int,
+                    flags_table_sorted['numflag_any_diagnostic_flag'],
+                    kind='nearest',
+                    bounds_error=False,
+                    fill_value='extrapolate'
+                )
+
+                # Interpolated flags
+                interpolated_flags = flag_interp_func(data_times_int)
+
+                # Define which columns to flag
+                required = lambda var: var != datetime_var and var in predefined_species
+                renaming_map = {var: f'numflag_{var}' for var in data_table.columns if required(var)}
+                variables = list(renaming_map.keys())
+
+                # Assign flags to those columns
+                for var in variables:
+                    data_table[var] = interpolated_flags
+
+                data_table.rename(columns=renaming_map, inplace=True)
+                
+            elif 'numflag_cpc' in flags_table.columns:
+                # Sort for interpolation
+                flags_table_sorted = flags_table.sort_values(flag_datetime_var)
+
+                # Pre-convert datetimes to int64 for interpolation
+                flag_times_int = flags_table_sorted[flag_datetime_var].values.astype(np.int64)
+                data_times_int = data_table[datetime_var].values.astype(np.int64)
+
+                # Nearest-neighbor interpolator
+                flag_interp_func = interp1d(
+                    flag_times_int,
+                    flags_table_sorted['numflag_cpc'],
+                    kind='nearest',
+                    bounds_error=False,
+                    fill_value='extrapolate'
+                )
+
+                # Interpolated flags
+                interpolated_cpc_flags = flag_interp_func(data_times_int)
+                    
 
-            # Assign the same flag values across required columns using vectorized operation
-            variables = list(renaming_map.keys())
-            data_table[variables] = np.tile(
-                flags_table['numflag_any_diagnostic_flag'].values[:, None], 
-                (1, len(variables))
-            )
-            #print(renaming_map)
-            data_table.rename(columns=renaming_map, inplace=True)
     else:
         raise FileNotFoundError("Automated diagnostic flag .csv not found. Hint: Run pipelines/step/generate_flags.py <campaignFile.h5> --flag-type diagnostics.")
 
 
     numflag_columns = [col for col in data_table.columns if 'numflag_' in col]
 
+    data_table = reconcile_flags(data_table, interpolated_cpc_flags, 0, interpolated_cpc_flags.size, numflag_columns)
+
     #print(numflag_columns)
     for flag_filename in manual_json_flags:
         #print(flag_filename)
@@ -196,27 +263,45 @@ with open(path_to_ebas_dict ,'r') as stream:
 
 # Vectorized function for getting the rank of a flag
 def get_rank(flag):
-    return flag_ranking.get(flag, np.nan)  # Default rank 0 for unknown flags
+    return flag_ranking.get(flag, -10)  # Default rank is NaN for unknown flags
 
 # Vectorized function for reconciling flags
 def reconcile_flags(data_table, flag_code, t1_idx, t2_idx, numflag_columns):
-    # Get the rank of the flag_code
-    flag_code_rank = get_rank(flag_code)
+    # Extract the relevant subtable
+    sub_table = data_table.loc[t1_idx:t2_idx, numflag_columns].copy()
 
-    # Extract the relevant subtable for efficiency
-    sub_table = data_table.loc[t1_idx:t2_idx, numflag_columns]
+    # Compute ranks of current values
+    current_ranks = np.vectorize(get_rank)(sub_table.values)
 
-    # Get the ranks for the current values in the subtable, using np.vectorize to avoid applymap
-    current_ranks = np.vectorize(get_rank)(sub_table.values)  # Element-wise rank computation
+    # Handle flag_code: broadcast scalar or reshape array
+    if np.isscalar(flag_code):
+        flag_code_values = np.full(sub_table.shape, flag_code)
+        flag_code_ranks = np.full(sub_table.shape, get_rank(flag_code))
+    else:
+        # Convert to NumPy array and ensure correct shape
+        flag_code_array = np.asarray(flag_code)
+        if flag_code_array.ndim == 1:
+            # Assume it's one flag per row — broadcast across columns
+            flag_code_values = np.tile(flag_code_array[:, None], (1, len(numflag_columns)))
+            flag_code_ranks = np.vectorize(get_rank)(flag_code_values)
+        else:
+            # Full 2D matrix
+            flag_code_values = flag_code_array
+            flag_code_ranks = np.vectorize(get_rank)(flag_code_array)
 
-    # Compare ranks: If the rank of the flag_code is higher, it will override the current value
-    new_values = np.where(current_ranks < flag_code_rank, flag_code, sub_table.values)
+        # Validate shape match
+        if flag_code_values.shape != sub_table.shape:
+            raise ValueError(f"Shape mismatch: expected {sub_table.shape}, got {flag_code_values.shape}")
 
-    # Update the dataframe with the new values
+    # Reconcile values based on rank comparison
+    new_values = np.where(current_ranks < flag_code_ranks, flag_code_values, sub_table.values)
+
+    # Assign reconciled values back
     data_table.loc[t1_idx:t2_idx, numflag_columns] = new_values.astype(np.int64)
 
     return data_table
 
+
 # all_dat[VaporizerTemp_C >= heater_lower_lim & VaporizerTemp_C <= heater_upper_lim ,flag_heater_auto:="V"]
 # all_dat[ABsamp >= AB_lower_lim & ABsamp <= AB_upper_lim ,flag_AB_auto:="V"]
 # all_dat[FlowRate_ccs >= flow_lower_lim & FlowRate_ccs <= flow_upper_lim ,flag_flow_auto:="V"]
@@ -248,6 +333,10 @@ def main(data_file, flag_type):
            keywords = [f'ACSM_{STATION_ABBR}_','_timeseries.txt/data_table']
            find_keyword = [all(keyword in item for keyword in keywords) for item in dataset_metadata_df['dataset_name']]
 
+        if flag_type == 'cpc':
+           keywords = ['cpc.particle_number_concentration.aerosol.', f'CH02L_TSI_3772_{STATION_ABBR}.CH02L_CPC.lev1.nas']
+           find_keyword = [all(keyword in item for keyword in keywords) for item in dataset_metadata_df['dataset_name']]
+
         # Specify source dataset to be extracted from input hdf5 data file
         columns = ['dataset_name','parent_file','parent_instrument']
         dataset_name, parent_file, parent_instrument = tuple(dataset_metadata_df.loc[find_keyword,col] for col in columns) 
@@ -316,6 +405,9 @@ def main(data_file, flag_type):
             #calib_param_dict = load_parameters(flag_type)     
             calib_param_dict = load_project_yaml_files(projectPath, "calibration_params.yaml")     
             flags_table = generate_species_flags(data_table,calib_param_dict,path_to_output_folder,datetime_var)
+        if flag_type == 'cpc':    
+            print(':D')
+            flags_table = generate_cpc_flags(data_table, datetime_var)
                 
         metadata = {'actris_level' : 1, 
             'processing_script': processingScriptRelPath.replace(os.sep,'/'),
@@ -361,7 +453,7 @@ def get_flags_from_folder(flagsFolderPath):
         if folderitem.startswith('flag') and folderitem.endswith('.json'):
             manual_json_flags.append(folderitem)
         # Identify CSV flag files
-        elif folderitem.endswith('.csv'):
+        elif folderitem.endswith('.csv') and '_flags' in folderitem:
             csv_flags.append(folderitem)
     
     # Return the lists of manual flag JSON files and CSV flag files
@@ -375,8 +467,8 @@ if __name__ == '__main__':
     parser.add_argument(
         "--flag-type",
         required=True,
-        choices=["diagnostics", "species", "cpd"],
-        help="Specify the flag type. Must be one of: diagnostics, species, cpd"
+        choices=["diagnostics", "species", "cpc"],
+        help="Specify the flag type. Must be one of: diagnostics, species, cpc"
     )
     parser.add_argument('data_file', type=str, help="Path to the input HDF5 file containing the data table.")
     #parser.add_argument('dataset_name', type=str, help ='Relative path to data_table (i.e., dataset name) in HDF5 file')