diff --git a/src/specificClass.js b/src/specificClass.js
index 6ef949c..8366ddd 100644
--- a/src/specificClass.js
+++ b/src/specificClass.js
@@ -211,7 +211,7 @@ class pumpingStation {
     this._updateVolumePrediction("in"); // check for changes in incomming flow
         //calc the most important values back to determine state and net up or downstream flow
     this._calcNetFlow();
-    this._calcTimeRemaining();
+    this._calcRemainingTime();
     
   }
   
diff --git a/test/specificClass.test.js b/test/specificClass.test.js
new file mode 100644
index 0000000..b4a477e
--- /dev/null
+++ b/test/specificClass.test.js
@@ -0,0 +1,260 @@
+/**
+ * Tests for pumpingStation specificClass (domain logic).
+ *
+ * The pumpingStation class manages a basin (wet well):
+ *  - initBasinProperties: derives surface area, volumes from config
+ *  - _calcVolumeFromLevel / _calcLevelFromVolume: linear geometry
+ *  - _calcDirection: filling / draining / stable from flow diff
+ *  - _callMeasurementHandler: dispatches to type-specific handlers
+ *  - getOutput: builds an output snapshot
+ */
+
+const PumpingStation = require('../src/specificClass');
+
+// --------------- helpers ---------------
+
+function makeConfig(overrides = {}) {
+  const base = {
+    general: {
+      name: 'TestStation',
+      id: 'ps-test-1',
+      unit: 'm3/h',
+      logging: { enabled: false, logLevel: 'error' },
+    },
+    functionality: {
+      softwareType: 'pumpingStation',
+      role: 'stationcontroller',
+      positionVsParent: 'atEquipment',
+    },
+    basin: {
+      volume: 50,       // m3  (empty basin volume)
+      height: 5,        // m
+      heightInlet: 0.3,  // m
+      heightOutlet: 0.2, // m
+      heightOverflow: 4.0, // m
+    },
+    hydraulics: {
+      refHeight: 'NAP',
+      basinBottomRef: 0,
+    },
+  };
+
+  for (const key of Object.keys(overrides)) {
+    if (typeof overrides[key] === 'object' && !Array.isArray(overrides[key]) && base[key]) {
+      base[key] = { ...base[key], ...overrides[key] };
+    } else {
+      base[key] = overrides[key];
+    }
+  }
+  return base;
+}
+
+// --------------- tests ---------------
+
+describe('pumpingStation specificClass', () => {
+
+  describe('constructor / initialization', () => {
+    it('should create an instance with the given config', () => {
+      const ps = new PumpingStation(makeConfig());
+      expect(ps).toBeDefined();
+      expect(ps.config.general.name).toBe('teststation');
+    });
+
+    it('should initialize state object with default values', () => {
+      const ps = new PumpingStation(makeConfig());
+      expect(ps.state).toEqual({ direction: '', netDownstream: 0, netUpstream: 0, seconds: 0 });
+    });
+
+    it('should initialize empty machines, stations, child, parent objects', () => {
+      const ps = new PumpingStation(makeConfig());
+      expect(ps.machines).toEqual({});
+      expect(ps.stations).toEqual({});
+      expect(ps.child).toEqual({});
+      expect(ps.parent).toEqual({});
+    });
+  });
+
+  describe('initBasinProperties()', () => {
+    it('should calculate surfaceArea = volume / height', () => {
+      const ps = new PumpingStation(makeConfig());
+      // 50 / 5 = 10 m2
+      expect(ps.basin.surfaceArea).toBe(10);
+    });
+
+    it('should calculate maxVol = height * surfaceArea', () => {
+      const ps = new PumpingStation(makeConfig());
+      // 5 * 10 = 50
+      expect(ps.basin.maxVol).toBe(50);
+    });
+
+    it('should calculate maxVolOverflow = heightOverflow * surfaceArea', () => {
+      const ps = new PumpingStation(makeConfig());
+      // 4.0 * 10 = 40
+      expect(ps.basin.maxVolOverflow).toBe(40);
+    });
+
+    it('should calculate minVol = heightOutlet * surfaceArea', () => {
+      const ps = new PumpingStation(makeConfig());
+      // 0.2 * 10 = 2
+      expect(ps.basin.minVol).toBeCloseTo(2, 5);
+    });
+
+    it('should calculate minVolOut = heightInlet * surfaceArea', () => {
+      const ps = new PumpingStation(makeConfig());
+      // 0.3 * 10 = 3
+      expect(ps.basin.minVolOut).toBeCloseTo(3, 5);
+    });
+
+    it('should store the raw config values on basin', () => {
+      const ps = new PumpingStation(makeConfig());
+      expect(ps.basin.volEmptyBasin).toBe(50);
+      expect(ps.basin.heightBasin).toBe(5);
+      expect(ps.basin.heightInlet).toBe(0.3);
+      expect(ps.basin.heightOutlet).toBe(0.2);
+      expect(ps.basin.heightOverflow).toBe(4.0);
+    });
+  });
+
+  describe('_calcVolumeFromLevel()', () => {
+    let ps;
+    beforeAll(() => { ps = new PumpingStation(makeConfig()); });
+
+    it('should return level * surfaceArea', () => {
+      // surfaceArea = 10, level = 2 => 20
+      expect(ps._calcVolumeFromLevel(2)).toBe(20);
+    });
+
+    it('should return 0 for level = 0', () => {
+      expect(ps._calcVolumeFromLevel(0)).toBe(0);
+    });
+
+    it('should clamp negative levels to 0', () => {
+      expect(ps._calcVolumeFromLevel(-3)).toBe(0);
+    });
+  });
+
+  describe('_calcLevelFromVolume()', () => {
+    let ps;
+    beforeAll(() => { ps = new PumpingStation(makeConfig()); });
+
+    it('should return volume / surfaceArea', () => {
+      // surfaceArea = 10, vol = 20 => 2
+      expect(ps._calcLevelFromVolume(20)).toBe(2);
+    });
+
+    it('should return 0 for volume = 0', () => {
+      expect(ps._calcLevelFromVolume(0)).toBe(0);
+    });
+
+    it('should clamp negative volumes to 0', () => {
+      expect(ps._calcLevelFromVolume(-10)).toBe(0);
+    });
+  });
+
+  describe('volume/level roundtrip', () => {
+    it('should roundtrip level -> volume -> level', () => {
+      const ps = new PumpingStation(makeConfig());
+      const level = 2.7;
+      const vol = ps._calcVolumeFromLevel(level);
+      const levelBack = ps._calcLevelFromVolume(vol);
+      expect(levelBack).toBeCloseTo(level, 10);
+    });
+  });
+
+  describe('_calcDirection()', () => {
+    let ps;
+    beforeAll(() => { ps = new PumpingStation(makeConfig()); });
+
+    it('should return "filling" for positive flow above threshold', () => {
+      expect(ps._calcDirection(0.01)).toBe('filling');
+    });
+
+    it('should return "draining" for negative flow below negative threshold', () => {
+      expect(ps._calcDirection(-0.01)).toBe('draining');
+    });
+
+    it('should return "stable" for flow near zero (within threshold)', () => {
+      expect(ps._calcDirection(0.0005)).toBe('stable');
+      expect(ps._calcDirection(-0.0005)).toBe('stable');
+      expect(ps._calcDirection(0)).toBe('stable');
+    });
+  });
+
+  describe('_callMeasurementHandler()', () => {
+    it('should not throw for flow and temperature measurement types', () => {
+      const ps = new PumpingStation(makeConfig());
+      // flow and temperature handlers are empty stubs, safe to call
+      expect(() => ps._callMeasurementHandler('flow', 0.5, 'downstream', {})).not.toThrow();
+      expect(() => ps._callMeasurementHandler('temperature', 15, 'atEquipment', {})).not.toThrow();
+    });
+
+    it('should dispatch to the correct handler based on measurement type', () => {
+      const ps = new PumpingStation(makeConfig());
+      // Verify the switch dispatches by checking it does not warn for known types
+      // pressure handler stores values and attempts coolprop calculation
+      // level handler stores values and computes volume
+      // We verify the dispatch logic by calling with type and checking no unhandled error
+      const spy = jest.spyOn(ps, 'updateMeasuredFlow');
+      ps._callMeasurementHandler('flow', 0.5, 'downstream', {});
+      expect(spy).toHaveBeenCalledWith(0.5, 'downstream', {});
+      spy.mockRestore();
+    });
+  });
+
+  describe('getOutput()', () => {
+    it('should return an object containing state and basin', () => {
+      const ps = new PumpingStation(makeConfig());
+      const out = ps.getOutput();
+      expect(out).toHaveProperty('state');
+      expect(out).toHaveProperty('basin');
+      expect(out.state).toBe(ps.state);
+      expect(out.basin).toBe(ps.basin);
+    });
+
+    it('should include measurement keys in the output', () => {
+      const ps = new PumpingStation(makeConfig());
+      const out = ps.getOutput();
+      // After initialization the predicted volume is set
+      expect(typeof out).toBe('object');
+    });
+  });
+
+  describe('_calcRemainingTime()', () => {
+    it('should not throw when called with a level and variant', () => {
+      const ps = new PumpingStation(makeConfig());
+      // Should not throw even with no measurement data; it will just find null diffs
+      expect(() => ps._calcRemainingTime(2, 'predicted')).not.toThrow();
+    });
+  });
+
+  describe('tick()', () => {
+    it('should call _updateVolumePrediction and _calcNetFlow', () => {
+      const ps = new PumpingStation(makeConfig());
+      const spyVol = jest.spyOn(ps, '_updateVolumePrediction');
+      const spyNet = jest.spyOn(ps, '_calcNetFlow');
+      // stub _calcRemainingTime to avoid needing full measurement data
+      ps._calcRemainingTime = jest.fn();
+      ps.tick();
+      expect(spyVol).toHaveBeenCalledWith('out');
+      expect(spyVol).toHaveBeenCalledWith('in');
+      expect(spyNet).toHaveBeenCalled();
+      spyVol.mockRestore();
+      spyNet.mockRestore();
+    });
+  });
+
+  describe('edge cases', () => {
+    it('should handle basin with zero height gracefully', () => {
+      // surfaceArea = volume / height => division by 0 gives Infinity
+      const config = makeConfig({ basin: { volume: 50, height: 0, heightInlet: 0, heightOutlet: 0, heightOverflow: 0 } });
+      const ps = new PumpingStation(config);
+      expect(ps.basin.surfaceArea).toBe(Infinity);
+    });
+
+    it('should handle basin with very small dimensions', () => {
+      const config = makeConfig({ basin: { volume: 0.001, height: 0.001, heightInlet: 0, heightOutlet: 0, heightOverflow: 0.0005 } });
+      const ps = new PumpingStation(config);
+      expect(ps.basin.surfaceArea).toBeCloseTo(1, 5);
+    });
+  });
+});