diff --git a/readers/NSIDataReader.py b/readers/NSIDataReader.py
new file mode 100644
index 0000000..1db7e23
--- /dev/null
+++ b/readers/NSIDataReader.py
@@ -0,0 +1,337 @@
+#   Copyright 2025 UKRI-STFC
+#   Copyright 2025 University of Manchester
+
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+
+#   http://www.apache.org/licenses/LICENSE-2.0
+
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+#
+# Authors:
+# Evan Kiely (WMG)
+
+from cil.framework import AcquisitionData, AcquisitionGeometry
+from cil.io.TIFF import TIFFStackReader
+import warnings
+import numpy as np
+import os
+    
+        
+class NSIDataReader(object):
+    
+    def __init__(self, 
+                 **kwargs):
+        '''Basic reader for xtekct files
+        
+        Parameters
+        ----------
+
+            
+        file_name: str with full path to file. TIFFs will be retrieved from the same path.
+            
+        roi: dictionary with roi to load 
+                {'angle': (start, end, step), 
+                 'horizontal': (start, end, step), 
+                 'vertical': (start, end, step)}
+                Files are stacked along axis_0. axis_1 and axis_2 correspond
+                to row and column dimensions, respectively.
+                Files are stacked in alphabetic order. 
+                To skip projections or to change number of projections to load, 
+                adjust 'angle'. For instance, 'angle': (100, 300)
+                will skip first 100 projections and will load 200 projections.
+                'angle': -1 is a shortcut to load all elements along axis.
+                Start and end can be specified as None which is equivalent 
+                to start = 0 and end = load everything to the end, respectively.
+                Start and end also can be negative.
+            
+        normalise: bool, normalises loaded projections by detector 
+                white level (I_0). Default value is True
+                            
+        fliplr: bool, default = False, flip projections in the left-right direction
+                (about vertical axis)
+                            
+        mode: str, 'bin' (default) or 'slice'. In bin mode, 'step' number
+                of pixels is binned together, values of resulting binned
+                pixels are calculated as average. 
+                In 'slice' mode 'step' defines standard numpy slicing.
+                Note: in general 
+                output array size in bin mode != output array size in slice mode
+        
+        Output
+        ------
+        
+        Acquisition data with corresponding geometry, arranged as ['angle', horizontal'] 
+        if a single slice is loaded and ['vertical, 'angle', horizontal'] 
+        if more than 1 slices are loaded.
+                    
+        '''
+        
+        self.file_name = kwargs.get('file_name', None)
+        self.roi = kwargs.get('roi', {'angle': -1, 'horizontal': -1, 'vertical': -1})
+        self.normalise = kwargs.get('normalise', True)
+        self.mode = kwargs.get('mode', 'bin')
+        self.fliplr = kwargs.get('fliplr', False)
+        
+        if self.file_name is not None:
+            self.set_up(file_name = self.file_name,
+                        roi = self.roi,
+                        normalise = self.normalise,
+                        mode = self.mode,
+                        fliplr = self.fliplr)
+            
+    def set_up(self, 
+               file_name = None, 
+               roi = {'angle': -1, 'horizontal': -1, 'vertical': -1},
+               normalise = True,
+               mode = 'bin',
+               fliplr = False):
+        
+        self.file_name = file_name
+        self.roi = roi
+        self.normalise = normalise
+        self.mode = mode
+        self.fliplr = fliplr
+        self.tiff_directory_path = os.path.dirname(self.file_name)
+
+        if self.file_name == None:
+            raise Exception('Path to file is required.')
+        
+        # check if data file exists
+        if not(os.path.isfile(self.file_name)):
+            raise Exception('File\n {}\n does not exist.'.format(self.file_name))
+                
+        # check labels     
+        for key in self.roi.keys():
+            if key not in ['angle', 'horizontal', 'vertical']:
+                raise Exception("Wrong label. One of the following is expected: angle, horizontal, vertical")
+        
+        roi = self.roi.copy()
+        
+        if 'angle' not in roi.keys():
+            roi['angle'] = -1
+            
+        if 'horizontal' not in roi.keys():
+            roi['horizontal'] = -1
+        
+        if 'vertical' not in roi.keys():
+            roi['vertical'] = -1
+                
+        # parse data file
+        with open(self.file_name, 'r', errors='replace') as f:
+            content = f.readlines()    
+                
+        content = [x.strip() for x in content]
+        
+        #initialise parameters
+        detector_offset_h = 0
+        detector_offset_v = 0
+        object_tilt_deg = 0
+        object_offset_x = None
+        object_roll_deg = None
+        centre_of_rotation_top = 0
+        centre_of_rotation_bottom = 0
+        angular_step = 0
+       
+        for line in content:
+            # number of projections
+            if line.startswith("<Number of projections>"):
+                num_projections = int(line.split('>')[1])
+
+            # number of pixels along Y axis
+            elif line.startswith("<width pixels>"):
+                pixel_num_h_0 = int(line.split('>')[1])
+                
+            # number of pixels along X axis
+            elif line.startswith("<height pixels>"):
+                pixel_num_v_0 = int(line.split('>')[1])
+                
+            # pixel size along X and y axis
+            elif line.startswith("<det pitch>"):
+                pixel_size_h_0 = float(line.split('>')[1])
+                pixel_size_v_0 = pixel_size_h_0
+                
+            elif line.startswith("<source to detector distance>"):
+                source_to_det = float(line.split('>')[1])
+                
+            # source to detector distance
+            elif line.startswith("<source to table distance>"):
+                source_to_origin = float(line.split('>')[1])
+                
+            # angular step
+            elif line.startswith("<angleStep>"):
+                if angular_step == 0:
+                    angular_step = float(line.split('>')[1])
+                
+          
+        self._experiment_name = 'scan'
+
+        self._roi_par = [[0, num_projections, 1] ,[0, pixel_num_v_0, 1], [0, pixel_num_h_0, 1]]
+        
+        for key in roi.keys():
+            if key == 'angle':
+                idx = 0
+            elif key == 'vertical':
+                idx = 1
+            elif key == 'horizontal':
+                idx = 2
+            if roi[key] != -1:
+                for i in range(2):
+                    if roi[key][i] != None:
+                        if roi[key][i] >= 0:
+                            self._roi_par[idx][i] = roi[key][i]
+                        else:
+                            self._roi_par[idx][i] = self._roi_par[idx][1]+roi[key][i]
+                if len(roi[key]) > 2:
+                    if roi[key][2] != None:
+                        if roi[key][2] > 0:
+                            self._roi_par[idx][2] = roi[key][2] 
+                        else:
+                            raise Exception("Negative step is not allowed")
+        
+        if self.mode == 'bin':
+            # calculate number of pixels and pixel size
+            pixel_num_v = (self._roi_par[1][1] - self._roi_par[1][0]) // self._roi_par[1][2]
+            pixel_num_h = (self._roi_par[2][1] - self._roi_par[2][0]) // self._roi_par[2][2]
+            pixel_size_v = pixel_size_v_0 * self._roi_par[1][2]
+            pixel_size_h = pixel_size_h_0 * self._roi_par[2][2]
+        else: # slice
+            pixel_num_v = int(np.ceil((self._roi_par[1][1] - self._roi_par[1][0]) / self._roi_par[1][2]))
+            pixel_num_h = int(np.ceil((self._roi_par[2][1] - self._roi_par[2][0]) / self._roi_par[2][2]))
+
+            pixel_size_v = pixel_size_v_0
+            pixel_size_h = pixel_size_h_0
+        
+        det_start_0 = -(pixel_num_h_0 / 2)
+        det_start = det_start_0 + self._roi_par[2][0]
+        det_end = det_start + pixel_num_h * self._roi_par[2][2]
+        det_pos_h = (det_start + det_end) * 0.5 * pixel_size_h_0 + detector_offset_h
+        
+        det_start_0 = -(pixel_num_v_0 / 2)
+        det_start = det_start_0 + self._roi_par[1][0]
+        det_end = det_start + pixel_num_v * self._roi_par[1][2]
+        det_pos_v = (det_start + det_end) * 0.5 * pixel_size_v_0 + detector_offset_v         
+
+        #angles from data file ignore *.ang and _ctdata.txt as not correct
+        angles = np.asarray( [ angular_step * proj for proj in range(num_projections) ] , dtype=np.float32)
+        
+        if self.mode == 'bin':
+            n_elem = (self._roi_par[0][1] - self._roi_par[0][0]) // self._roi_par[0][2]
+            shape = (n_elem, self._roi_par[0][2])
+            angles = angles[self._roi_par[0][0]:(self._roi_par[0][0] + n_elem * self._roi_par[0][2])].reshape(shape).mean(1)
+        else:
+            angles = angles[slice(self._roi_par[0][0], self._roi_par[0][1], self._roi_par[0][2])]
+        
+
+        if object_offset_x == None:
+            object_offset_x = (centre_of_rotation_bottom+centre_of_rotation_top)* 0.5 *  source_to_origin /source_to_det
+
+        if object_roll_deg == None:
+            x = (centre_of_rotation_top-centre_of_rotation_bottom)
+            y = pixel_num_v_0 * pixel_size_v_0
+            object_roll = -np.arctan2(x, y)
+        else:
+            object_roll = object_roll_deg * np.pi /180.
+
+        object_tilt = -object_tilt_deg * np.pi /180.
+
+        tilt_matrix = np.eye(3)
+        tilt_matrix[1][1] = tilt_matrix[2][2] = np.cos(object_tilt)
+        tilt_matrix[1][2] = -np.sin(object_tilt)
+        tilt_matrix[2][1] = np.sin(object_tilt)
+
+        roll_matrix = np.eye(3)
+        roll_matrix[0][0] = roll_matrix[2][2] = np.cos(object_roll)
+        roll_matrix[0][2] = np.sin(object_roll)
+        roll_matrix[2][0] = -np.sin(object_roll)
+
+        #order of construction may be reversed, but unlikely to have both in a dataset
+        rot_matrix = np.matmul(tilt_matrix,roll_matrix)
+        rotation_axis_direction = rot_matrix.dot([0,0,1])
+
+
+        if self.fliplr:
+            origin = 'top-left'
+        else:
+            origin = 'top-right'
+
+        if pixel_num_v == 1 and (self._roi_par[1][0]+self._roi_par[1][1]) // 2 == pixel_num_v_0 // 2:
+            self._ag = AcquisitionGeometry.create_Cone2D(source_position=[0, -source_to_origin],
+                                                     rotation_axis_position=[-object_offset_x, 0],
+                                                     detector_position=[-det_pos_h, source_to_det-source_to_origin])
+            self._ag.set_angles(angles, 
+                                angle_unit='degree')
+            
+            self._ag.set_panel(pixel_num_h, pixel_size=pixel_size_h, origin=origin)
+
+            self._ag.set_labels(labels=['angle', 'horizontal'])
+        else:
+            self._ag = AcquisitionGeometry.create_Cone3D(source_position=[0, -source_to_origin, 0],
+                                                         rotation_axis_position=[-object_offset_x, 0, 0],
+                                                         rotation_axis_direction=rotation_axis_direction,
+                                                         detector_position=[-det_pos_h, source_to_det-source_to_origin, det_pos_v])
+            self._ag.set_angles(angles, 
+                                angle_unit='degree')
+            
+            self._ag.set_panel(( pixel_num_h, pixel_num_v),
+                               pixel_size=( pixel_size_v, pixel_size_h),
+                               origin=origin)
+        
+            self._ag.set_labels(labels=['angle',   'vertical', 'horizontal'])
+
+    def get_geometry(self):
+        
+        '''
+        Return AcquisitionGeometry object
+        '''
+        
+        return self._ag
+    def get_roi(self):
+        '''returns the roi'''
+        roi = self._roi_par[:]
+        if self._ag.dimension == '2D':
+            roi.pop(1)
+
+        roidict = {}
+        for i,el in enumerate(roi):
+            # print (i, el)
+            roidict['axis_{}'.format(i)] = tuple(el)
+        return roidict
+
+    def read(self):
+        
+        '''
+        Reads projections and return AcquisitionData container
+        '''
+        
+        reader = TIFFStackReader()
+
+        roi = self.get_roi()
+
+        reader.set_up(file_name = self.tiff_directory_path,
+                      roi=roi, mode=self.mode)
+
+        ad = reader.read_as_AcquisitionData(self._ag)
+              
+        if (self.normalise):
+            #ad.array[ad.array < 1] = 1
+            # cast the data read to float32
+            ad = ad / np.float32(float(1))
+            
+        
+        if self.fliplr:
+            dim = ad.get_dimension_axis('horizontal')
+            ad.array = np.flip(ad.array, dim)
+        
+        return ad
+
+    def load_projections(self):
+        '''alias of read for backward compatibility'''
+        return self.read()
+
+