diff --git a/src/hyperion/parameters/components.py b/src/hyperion/parameters/components.py
index dfc0fa8ce..b8885e139 100644
--- a/src/hyperion/parameters/components.py
+++ b/src/hyperion/parameters/components.py
@@ -152,7 +152,6 @@ class DiffractionExperiment(HyperionParameters):
         default=CONST.PARAM.DETECTOR.BEAM_XY_LUT_PATH
     )
     zocalo_environment: str = Field(default=CONST.ZOCALO_ENV)
-    detector: str = Field(default=CONST.I03.DETECTOR)
     trigger_mode: TriggerMode = Field(default=TriggerMode.FREE_RUN)
     detector_distance_mm: float | None = Field(default=None, gt=0)
     demand_energy_ev: float | None = Field(default=None, gt=0)
diff --git a/src/hyperion/parameters/gridscan.py b/src/hyperion/parameters/gridscan.py
index bff47c574..ec345f34d 100644
--- a/src/hyperion/parameters/gridscan.py
+++ b/src/hyperion/parameters/gridscan.py
@@ -25,7 +25,7 @@
     WithScan,
     XyzStarts,
 )
-from hyperion.parameters.constants import CONST
+from hyperion.parameters.constants import CONST, I03Constants
 
 
 class GridCommon(
@@ -73,7 +73,7 @@ def detector_params(self):
         ), "Detector distance must be filled before generating DetectorParams"
         os.makedirs(self.storage_directory, exist_ok=True)
         return DetectorParams(
-            detector_size_constants=self.detector,  # type: ignore # Will be cleaned up in #1307
+            detector_size_constants=I03Constants.DETECTOR,
             expected_energy_ev=self.demand_energy_ev,
             exposure_time=self.exposure_time_s,
             directory=self.storage_directory,
diff --git a/tests/test_data/parameter_json_files/good_test_grid_with_edge_detect_parameters.json b/tests/test_data/parameter_json_files/good_test_grid_with_edge_detect_parameters.json
index 7084cdf39..e6492a1d8 100644
--- a/tests/test_data/parameter_json_files/good_test_grid_with_edge_detect_parameters.json
+++ b/tests/test_data/parameter_json_files/good_test_grid_with_edge_detect_parameters.json
@@ -2,7 +2,6 @@
     "parameter_model_version": "5.0.0",
     "beamline": "BL03S",
     "insertion_prefix": "SR03S",
-    "detector": "EIGER2_X_16M",
     "zocalo_environment": "devrmq",
     "storage_directory": "/tmp",
     "file_name": "file_name",
diff --git a/tests/test_data/parameter_json_files/good_test_pin_centre_then_xray_centre_parameters.json b/tests/test_data/parameter_json_files/good_test_pin_centre_then_xray_centre_parameters.json
index 9aaf5ad10..e0c67f70d 100644
--- a/tests/test_data/parameter_json_files/good_test_pin_centre_then_xray_centre_parameters.json
+++ b/tests/test_data/parameter_json_files/good_test_pin_centre_then_xray_centre_parameters.json
@@ -2,7 +2,6 @@
     "parameter_model_version": "5.0.0",
     "beamline": "BL03S",
     "insertion_prefix": "SR03S",
-    "detector": "EIGER2_X_16M",
     "zocalo_environment": "devrmq",
     "storage_directory": "/tmp",
     "file_name": "file_name",
diff --git a/tests/test_data/parameter_json_files/good_test_rotation_scan_parameters.json b/tests/test_data/parameter_json_files/good_test_rotation_scan_parameters.json
index b05a6f97f..2e728e688 100644
--- a/tests/test_data/parameter_json_files/good_test_rotation_scan_parameters.json
+++ b/tests/test_data/parameter_json_files/good_test_rotation_scan_parameters.json
@@ -4,7 +4,6 @@
     "det_dist_to_beam_converter_path": "tests/test_data/test_lookup_table.txt",
     "storage_directory": "/tmp/dls/i03/data/2024/cm31105-4/auto/123456/",
     "detector_distance_mm": 100.0,
-    "detector": "EIGER2_X_16M",
     "demand_energy_ev": 100,
     "exposure_time_s": 0.1,
     "insertion_prefix": "SR03S",
diff --git a/tests/test_data/parameter_json_files/good_test_rotation_scan_parameters_nomove.json b/tests/test_data/parameter_json_files/good_test_rotation_scan_parameters_nomove.json
index ae9a36940..a655bcaaa 100644
--- a/tests/test_data/parameter_json_files/good_test_rotation_scan_parameters_nomove.json
+++ b/tests/test_data/parameter_json_files/good_test_rotation_scan_parameters_nomove.json
@@ -4,7 +4,6 @@
     "det_dist_to_beam_converter_path": "tests/test_data/test_lookup_table.txt",
     "storage_directory": "/tmp/dls/i03/data/2024/cm31105-4/auto/123456/",
     "detector_distance_mm": 100.0,
-    "detector": "EIGER2_X_16M",
     "demand_energy_ev": 100,
     "exposure_time_s": 0.1,
     "insertion_prefix": "SR03S",
diff --git a/tests/test_data/parameter_json_files/ispyb_gridscan_system_test_parameters.json b/tests/test_data/parameter_json_files/ispyb_gridscan_system_test_parameters.json
index d34ff020e..c93653c42 100644
--- a/tests/test_data/parameter_json_files/ispyb_gridscan_system_test_parameters.json
+++ b/tests/test_data/parameter_json_files/ispyb_gridscan_system_test_parameters.json
@@ -2,7 +2,6 @@
     "parameter_model_version": "5.0.0",
     "beamline": "BL03S",
     "insertion_prefix": "SR03S",
-    "detector": "EIGER2_X_16M",
     "zocalo_environment": "dev_artemis",
     "storage_directory": "/tmp",
     "file_name": "file_name",
diff --git a/tests/unit_tests/experiment_plans/test_flyscan_xray_centre_plan.py b/tests/unit_tests/experiment_plans/test_flyscan_xray_centre_plan.py
index 9e40bae03..e2063f093 100644
--- a/tests/unit_tests/experiment_plans/test_flyscan_xray_centre_plan.py
+++ b/tests/unit_tests/experiment_plans/test_flyscan_xray_centre_plan.py
@@ -12,8 +12,6 @@
 from dodal.beamlines import i03
 from dodal.common.beamlines.beamline_utils import clear_device
 from dodal.devices.detector.det_dim_constants import (
-    EIGER2_X_4M_DIMENSION,
-    EIGER_TYPE_EIGER2_X_4M,
     EIGER_TYPE_EIGER2_X_16M,
 )
 from dodal.devices.fast_grid_scan import FastGridScan
@@ -63,7 +61,6 @@
 from hyperion.parameters.gridscan import ThreeDGridScan
 from tests.conftest import create_dummy_scan_spec
 
-from ...conftest import default_raw_params
 from ...system_tests.external_interaction.conftest import (
     TEST_RESULT_LARGE,
     TEST_RESULT_MEDIUM,
@@ -120,7 +117,7 @@ def mock_ispyb():
 class TestFlyscanXrayCentrePlan:
     td: TestData = TestData()
 
-    def test_given_full_parameters_dict_when_detector_name_used_and_converted_then_detector_constants_correct(
+    def test_eiger2_x_16_detector_specified(
         self,
         test_fgs_params: ThreeDGridScan,
     ):
@@ -128,11 +125,6 @@ def test_given_full_parameters_dict_when_detector_name_used_and_converted_then_d
             test_fgs_params.detector_params.detector_size_constants.det_type_string
             == EIGER_TYPE_EIGER2_X_16M
         )
-        raw_params_dict = default_raw_params()
-        raw_params_dict["detector"] = EIGER_TYPE_EIGER2_X_4M
-        params: ThreeDGridScan = ThreeDGridScan(**raw_params_dict)
-        det_dimension = params.detector_params.detector_size_constants.det_dimension
-        assert det_dimension == EIGER2_X_4M_DIMENSION
 
     def test_when_run_gridscan_called_then_generator_returned(
         self,
diff --git a/tests/unit_tests/experiment_plans/test_panda_flyscan_xray_centre_plan.py b/tests/unit_tests/experiment_plans/test_panda_flyscan_xray_centre_plan.py
index 830e129ad..fb48431d9 100644
--- a/tests/unit_tests/experiment_plans/test_panda_flyscan_xray_centre_plan.py
+++ b/tests/unit_tests/experiment_plans/test_panda_flyscan_xray_centre_plan.py
@@ -8,11 +8,7 @@
 import pytest
 from bluesky.run_engine import RunEngine
 from bluesky.utils import Msg
-from dodal.devices.detector.det_dim_constants import (
-    EIGER2_X_4M_DIMENSION,
-    EIGER_TYPE_EIGER2_X_4M,
-    EIGER_TYPE_EIGER2_X_16M,
-)
+from dodal.devices.detector.det_dim_constants import EIGER_TYPE_EIGER2_X_16M
 from dodal.devices.panda_fast_grid_scan import PandAFastGridScan
 from dodal.devices.synchrotron import SynchrotronMode
 from ophyd.sim import make_fake_device
@@ -53,7 +49,6 @@
 from hyperion.parameters.constants import CONST
 from hyperion.parameters.gridscan import ThreeDGridScan
 
-from ...conftest import default_raw_params
 from ...system_tests.external_interaction.conftest import (
     TEST_RESULT_LARGE,
     TEST_RESULT_MEDIUM,
@@ -103,7 +98,7 @@ def standalone_read_hardware_for_ispyb(
 class TestFlyscanXrayCentrePlan:
     td: TestData = TestData()
 
-    def test_given_full_parameters_dict_when_detector_name_used_and_converted_then_detector_constants_correct(
+    def test_eiger2_x_16_detector_specified(
         self,
         test_panda_fgs_params: ThreeDGridScan,
     ):
@@ -111,11 +106,6 @@ def test_given_full_parameters_dict_when_detector_name_used_and_converted_then_d
             test_panda_fgs_params.detector_params.detector_size_constants.det_type_string
             == EIGER_TYPE_EIGER2_X_16M
         )
-        raw_params_dict = default_raw_params()
-        raw_params_dict["detector"] = EIGER_TYPE_EIGER2_X_4M
-        params: ThreeDGridScan = ThreeDGridScan(**raw_params_dict)
-        det_dimension = params.detector_params.detector_size_constants.det_dimension
-        assert det_dimension == EIGER2_X_4M_DIMENSION
 
     def test_when_run_gridscan_called_then_generator_returned(
         self,