diff --git a/tests/loader/flash/test_flash_loader.py b/tests/loader/flash/test_flash_loader.py
new file mode 100644
index 00000000..84119aa0
--- /dev/null
+++ b/tests/loader/flash/test_flash_loader.py
@@ -0,0 +1,71 @@
+import os
+from importlib.util import find_spec
+from pathlib import Path
+
+import pytest
+
+from sed.core.config import parse_config
+from sed.loader.flash.loader import FlashLoader
+
+package_dir = os.path.dirname(find_spec("sed").origin)
+config_path = os.path.join(package_dir, "../tests/data/loader/flash/config.yaml")
+
+
+@pytest.fixture
+def config_file():
+    return parse_config(config_path)
+
+
+def test_get_channels_by_format(config_file):
+
+    fl = FlashLoader(config_file)
+    electron_channels = ["dldPosX", "dldPosY", "dldTimeSteps"]
+    pulse_channels = [
+        "sampleBias",
+        "tofVoltage",
+        "extractorVoltage",
+        "extractorCurrent",
+        "cryoTemperature",
+        "sampleTemperature",
+        "dldTimeBinSize",
+    ]
+
+    # Call get_channels_by_format method
+    format_electron = fl.get_channels_by_format(["per_electron"])
+    format_pulse = fl.get_channels_by_format(["per_pulse"])
+    format_both = fl.get_channels_by_format(["per_pulse", "per_electron"])
+
+    assert set(electron_channels) == set(format_electron)
+    assert set(pulse_channels) == set(format_pulse)
+    assert set(electron_channels + pulse_channels) == set(format_both)
+
+
+@pytest.mark.parametrize(
+    "sub_dir",
+    ["online-0/fl1user3/", "express-0/fl1user3/", "FL1USER3/"],
+)
+def test_initialize_paths(config_file, fs, sub_dir):
+    config = config_file
+    del config["core"]["paths"]
+    config["core"]["beamtime_id"] = "12345678"
+    config["core"]["year"] = "2000"
+
+    # find base path of beamline from config. here we use pg2
+    base_path = config["dataframe"]["beamtime_dir"]["pg2"]
+    expected_path = (
+        Path(base_path) / config["core"]["year"] / "data" / config["core"]["beamtime_id"]
+    )
+    # create expected paths
+    expected_raw_path = expected_path / "raw" / "hdf" / sub_dir
+    expected_processed_path = expected_path / "processed" / "parquet"
+
+    # create fake file system for testing
+    fs.create_dir(expected_raw_path)
+    fs.create_dir(expected_processed_path)
+
+    # instance of class with correct config and call initialize_paths
+    fl = FlashLoader(config=config)
+    data_raw_dir, data_parquet_dir = fl.initialize_paths()
+    print(data_raw_dir)
+    assert expected_raw_path == data_raw_dir[0]
+    assert expected_processed_path == data_parquet_dir