diff --git a/api/api.yaml b/api/api.yaml
index c0a5441..9090378 100644
--- a/api/api.yaml
+++ b/api/api.yaml
@@ -54,7 +54,6 @@ tags:
   - name: /
   - name: /sample
   - name: /material
-  - name: /condition
   - name: /measurement
   - name: /template
   - name: /model
diff --git a/api/schemas.yaml b/api/schemas.yaml
index 6e1eeb7..e76cfb0 100644
--- a/api/schemas.yaml
+++ b/api/schemas.yaml
@@ -133,7 +133,7 @@ Measurement:
   allOf:
     - $ref: 'api.yaml#/components/schemas/_Id'
   properties:
-    condition_id:
+    sample_id:
       $ref: 'api.yaml#/components/schemas/Id'
     values:
       type: object
diff --git a/src/index.ts b/src/index.ts
index 1343442..55ca5ff 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -12,6 +12,7 @@ import db from './db';
 // TODO: condition values not needed on initial add
 // TODO: add multiple samples at once
 // TODO: coverage
+// TODO: think about the display of deleted/new samples and validation in data and UI
 
 // tell if server is running in debug or production environment
 console.info(process.env.NODE_ENV === 'production' ? '===== PRODUCTION =====' : process.env.NODE_ENV === 'test' ? '' :'===== DEVELOPMENT =====');
diff --git a/src/models/measurement.ts b/src/models/measurement.ts
index 7db0a50..4282b29 100644
--- a/src/models/measurement.ts
+++ b/src/models/measurement.ts
@@ -9,6 +9,6 @@ const MeasurementSchema = new mongoose.Schema({
   values: mongoose.Schema.Types.Mixed,
   measurement_template: {type: mongoose.Schema.Types.ObjectId, ref: MeasurementTemplateModel},
   status: Number
-});
+}, {minimize: false});
 
 export default mongoose.model('measurement', MeasurementSchema);
\ No newline at end of file
diff --git a/src/routes/measurement.spec.ts b/src/routes/measurement.spec.ts
index 8ca49ed..6e58290 100644
--- a/src/routes/measurement.spec.ts
+++ b/src/routes/measurement.spec.ts
@@ -3,7 +3,7 @@ import MeasurementModel from '../models/measurement';
 import TestHelper from "../test/helper";
 import globals from '../globals';
 
-// TODO: allow empty values
+// TODO: restore measurements for m/a
 
 
 describe('/measurement', () => {
@@ -19,7 +19,7 @@ describe('/measurement', () => {
         url: '/measurement/800000000000000000000001',
         auth: {basic: 'janedoe'},
         httpStatus: 200,
-        res: {_id: '800000000000000000000001', condition_id: '700000000000000000000001', values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}, measurement_template: '300000000000000000000001'}
+        res: {_id: '800000000000000000000001', sample_id: '400000000000000000000001', values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}, measurement_template: '300000000000000000000001'}
       });
     });
     it('returns the measurement for an API key', done => {
@@ -28,7 +28,24 @@ describe('/measurement', () => {
         url: '/measurement/800000000000000000000001',
         auth: {key: 'janedoe'},
         httpStatus: 200,
-        res: {_id: '800000000000000000000001', condition_id: '700000000000000000000001', values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}, measurement_template: '300000000000000000000001'}
+        res: {_id: '800000000000000000000001', sample_id: '400000000000000000000001', values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}, measurement_template: '300000000000000000000001'}
+      });
+    });
+    it('returns deleted measurements for a maintain/admin user', done => {
+      TestHelper.request(server, done, {
+        method: 'get',
+        url: '/measurement/800000000000000000000004',
+        auth: {basic: 'admin'},
+        httpStatus: 200,
+        res: {_id: '800000000000000000000004', sample_id: '400000000000000000000003', values: {val1: 1}, measurement_template: '300000000000000000000003'}
+      });
+    });
+    it('rejects requests for deleted measurements from a write user', done => {
+      TestHelper.request(server, done, {
+        method: 'get',
+        url: '/measurement/800000000000000000000004',
+        auth: {basic: 'janedoe'},
+        httpStatus: 403
       });
     });
     it('rejects an invalid id', done => {
@@ -64,7 +81,7 @@ describe('/measurement', () => {
         auth: {basic: 'janedoe'},
         httpStatus: 200,
         req: {},
-        res: {_id: '800000000000000000000001', condition_id: '700000000000000000000001', values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}, measurement_template: '300000000000000000000001'}
+        res: {_id: '800000000000000000000001', sample_id: '400000000000000000000001', values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}, measurement_template: '300000000000000000000001'}
       });
     });
     it('keeps unchanged values', done => {
@@ -76,7 +93,7 @@ describe('/measurement', () => {
         req: {values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}}
       }).end((err, res) => {
         if (err) return done(err);
-        should(res.body).be.eql({_id: '800000000000000000000001', condition_id: '700000000000000000000001', values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}, measurement_template: '300000000000000000000001'});
+        should(res.body).be.eql({_id: '800000000000000000000001', sample_id: '400000000000000000000001', values: {dpt: [[3997.12558,98.00555],[3995.08519,98.03253],[3993.04480,98.02657]]}, measurement_template: '300000000000000000000001'});
         MeasurementModel.findById('800000000000000000000001').lean().exec((err, data: any) => {
           if (err) return done(err);
           should(data).have.property('status',globals.status.validated);
@@ -93,7 +110,7 @@ describe('/measurement', () => {
         req: {values: {'weight %': 0.5}}
       }).end((err, res) => {
         if (err) return done(err);
-        should(res.body).be.eql({_id: '800000000000000000000002', condition_id: '700000000000000000000002', values: {'weight %': 0.5, 'standard deviation': 0.2}, measurement_template: '300000000000000000000002'});
+        should(res.body).be.eql({_id: '800000000000000000000002', sample_id: '400000000000000000000002', values: {'weight %': 0.5, 'standard deviation': 0.2}, measurement_template: '300000000000000000000002'});
         MeasurementModel.findById('800000000000000000000002').lean().exec((err, data: any) => {
           if (err) return done(err);
           should(data).have.property('status',globals.status.validated);
@@ -110,10 +127,10 @@ describe('/measurement', () => {
         req: {values: {dpt: [[1,2],[3,4],[5,6]]}}
       }).end((err, res) => {
         if (err) return done(err);
-        should(res.body).be.eql({_id: '800000000000000000000001', condition_id: '700000000000000000000001', values: {dpt: [[1,2],[3,4],[5,6]]}, measurement_template: '300000000000000000000001'});
+        should(res.body).be.eql({_id: '800000000000000000000001', sample_id: '400000000000000000000001', values: {dpt: [[1,2],[3,4],[5,6]]}, measurement_template: '300000000000000000000001'});
         MeasurementModel.findById('800000000000000000000001').lean().exec((err, data: any) => {
-          should(data).have.only.keys('_id', 'condition_id', 'values', 'measurement_template', 'status', '__v');
-          should(data.condition_id.toString()).be.eql('700000000000000000000001');
+          should(data).have.only.keys('_id', 'sample_id', 'values', 'measurement_template', 'status', '__v');
+          should(data.sample_id.toString()).be.eql('400000000000000000000001');
           should(data.measurement_template.toString()).be.eql('300000000000000000000001');
           should(data).have.property('status',globals.status.new);
           should(data).have.property('values');
@@ -129,7 +146,17 @@ describe('/measurement', () => {
         auth: {basic: 'janedoe'},
         httpStatus: 200,
         req: {values: {'weight %': 0.9}},
-        res: {_id: '800000000000000000000002', condition_id: '700000000000000000000002', values: {'weight %': 0.9, 'standard deviation': 0.2}, measurement_template: '300000000000000000000002'}
+        res: {_id: '800000000000000000000002', sample_id: '400000000000000000000002', values: {'weight %': 0.9, 'standard deviation': 0.2}, measurement_template: '300000000000000000000002'}
+      });
+    });
+    it('allows keeping empty values empty', done => {
+      TestHelper.request(server, done, {
+        method: 'put',
+        url: '/measurement/800000000000000000000005',
+        auth: {basic: 'janedoe'},
+        httpStatus: 200,
+        req: {values: {'weight %': 0.9}},
+        res: {_id: '800000000000000000000005', sample_id: '400000000000000000000002', values: {'weight %': 0.9, 'standard deviation': null}, measurement_template: '300000000000000000000002'}
       });
     });
     it('rejects not specified values', done => {
@@ -149,7 +176,7 @@ describe('/measurement', () => {
         auth: {basic: 'admin'},
         httpStatus: 400,
         req: {values: {val1: 4}},
-        res: {status: 'Invalid body format', details: '"val1" must be one of [1, 2, 3]'}
+        res: {status: 'Invalid body format', details: '"val1" must be one of [1, 2, 3, null]'}
       });
     });
     it('rejects a value below minimum range', done => {
@@ -182,6 +209,16 @@ describe('/measurement', () => {
         res: {status: 'Invalid body format', details: '"measurement_template" is not allowed'}
       });
     });
+    it('rejects a new sample id', done => {
+      TestHelper.request(server, done, {
+        method: 'put',
+        url: '/measurement/800000000000000000000002',
+        auth: {basic: 'janedoe'},
+        httpStatus: 400,
+        req: {values: {'weight %': 0.9, 'standard deviation': 0.3}, sample_id: '400000000000000000000002'},
+        res: {status: 'Invalid body format', details: '"sample_id" is not allowed'}
+      });
+    });
     it('rejects editing a measurement for a write user who did not create this measurement', done => {
       TestHelper.request(server, done, {
         method: 'put',
@@ -198,7 +235,7 @@ describe('/measurement', () => {
         auth: {basic: 'admin'},
         httpStatus: 200,
         req: {values: {'weight %': 0.9, 'standard deviation': 0.3}},
-        res: {_id: '800000000000000000000002', condition_id: '700000000000000000000002', values: {'weight %': 0.9, 'standard deviation': 0.3}, measurement_template: '300000000000000000000002'}
+        res: {_id: '800000000000000000000002', sample_id: '400000000000000000000002', values: {'weight %': 0.9, 'standard deviation': 0.3}, measurement_template: '300000000000000000000002'}
       });
     });
     it('rejects an invalid id', done => {
@@ -327,12 +364,12 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 200,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
       }).end((err, res) => {
         if (err) return done(err);
-        should(res.body).have.only.keys('_id', 'condition_id', 'values', 'measurement_template');
+        should(res.body).have.only.keys('_id', 'sample_id', 'values', 'measurement_template');
         should(res.body).have.property('_id').be.type('string');
-        should(res.body).have.property('condition_id', '700000000000000000000001');
+        should(res.body).have.property('sample_id', '400000000000000000000001');
         should(res.body).have.property('measurement_template', '300000000000000000000002');
         should(res.body).have.property('values');
         should(res.body.values).have.property('weight %', 0.8);
@@ -346,13 +383,13 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 200,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
       }).end((err, res) => {
         if (err) return done(err);
         MeasurementModel.findById(res.body._id).lean().exec((err, data: any) => {
           if (err) return done(err);
-          should(data).have.only.keys('_id', 'condition_id', 'values', 'measurement_template', 'status', '__v');
-          should(data.condition_id.toString()).be.eql('700000000000000000000001');
+          should(data).have.only.keys('_id', 'sample_id', 'values', 'measurement_template', 'status', '__v');
+          should(data.sample_id.toString()).be.eql('400000000000000000000001');
           should(data.measurement_template.toString()).be.eql('300000000000000000000002');
           should(data).have.property('status', 0);
           should(data).have.property('values');
@@ -362,24 +399,24 @@ describe('/measurement', () => {
         });
       });
     });
-    it('rejects an invalid condition id', done => {
+    it('rejects an invalid sample id', done => {
       TestHelper.request(server, done, {
         method: 'post',
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '700000000000h00000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'},
-        res: {status: 'Invalid body format', details: '"condition_id" with value "700000000000h00000000001" fails to match the required pattern: /[0-9a-f]{24}/'}
+        req: {sample_id: '400000000000h00000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'},
+        res: {status: 'Invalid body format', details: '"sample_id" with value "400000000000h00000000001" fails to match the required pattern: /[0-9a-f]{24}/'}
       });
     });
-    it('rejects a condition id not available', done => {
+    it('rejects a sample id not available', done => {
       TestHelper.request(server, done, {
         method: 'post',
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '000000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'},
-        res: {status: 'Condition id not available'}
+        req: {sample_id: '000000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'},
+        res: {status: 'Sample id not available'}
       });
     });
     it('rejects an invalid measurement_template id', done => {
@@ -388,7 +425,7 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '30000000000h000000000002'},
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '30000000000h000000000002'},
         res: {status: 'Invalid body format', details: '"measurement_template" with value "30000000000h000000000002" fails to match the required pattern: /[0-9a-f]{24}/'}
       });
     });
@@ -398,7 +435,7 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '000000000000000000000002'},
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '000000000000000000000002'},
         res: {status: 'Measurement template not available'}
       });
     });
@@ -408,18 +445,27 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1, xx: 44}, measurement_template: '300000000000000000000002'},
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1, xx: 44}, measurement_template: '300000000000000000000002'},
         res: {status: 'Invalid body format', details: '"xx" is not allowed'}
       });
     });
-    it('rejects missing values', done => {
+    it('accepts missing values', done => {
       TestHelper.request(server, done, {
         method: 'post',
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
-        httpStatus: 400,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8}, measurement_template: '300000000000000000000002'},
-        res: {status: 'Invalid body format', details: '"standard deviation" is required'}
+        httpStatus: 200,
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8}, measurement_template: '300000000000000000000002'}
+      }).end((err, res) => {
+        if (err) return done(err);
+        should(res.body).have.only.keys('_id', 'sample_id', 'values', 'measurement_template');
+        should(res.body).have.property('_id').be.type('string');
+        should(res.body).have.property('sample_id', '400000000000000000000001');
+        should(res.body).have.property('measurement_template', '300000000000000000000002');
+        should(res.body).have.property('values');
+        should(res.body.values).have.property('weight %', 0.8);
+        should(res.body.values).have.property('standard deviation', null);
+        done();
       });
     });
     it('rejects a value not in the value range', done => {
@@ -428,8 +474,8 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '700000000000000000000001', values: {val1: 4}, measurement_template: '300000000000000000000003'},
-        res: {status: 'Invalid body format', details: '"val1" must be one of [1, 2, 3]'}
+        req: {sample_id: '400000000000000000000001', values: {val1: 4}, measurement_template: '300000000000000000000003'},
+        res: {status: 'Invalid body format', details: '"val1" must be one of [1, 2, 3, null]'}
       });
     });
     it('rejects a value below minimum range', done => {
@@ -438,7 +484,7 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': -1, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'},
+        req: {sample_id: '400000000000000000000001', values: {'weight %': -1, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'},
         res: {status: 'Invalid body format', details: '"weight %" must be larger than or equal to 0'}
       });
     });
@@ -448,18 +494,18 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 2}, measurement_template: '300000000000000000000002'},
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 2}, measurement_template: '300000000000000000000002'},
         res: {status: 'Invalid body format', details: '"standard deviation" must be less than or equal to 0.5'}
       });
     });
-    it('rejects a missing condition id', done => {
+    it('rejects a missing sample id', done => {
       TestHelper.request(server, done, {
         method: 'post',
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
         req: {values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'},
-        res: {status: 'Invalid body format', details: '"condition_id" is required'}
+        res: {status: 'Invalid body format', details: '"sample_id" is required'}
       });
     });
     it('rejects a missing measurement_template', done => {
@@ -468,7 +514,7 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 400,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}},
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}},
         res: {status: 'Invalid body format', details: '"measurement_template" is required'}
       });
     });
@@ -478,7 +524,7 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'janedoe'},
         httpStatus: 403,
-        req: {condition_id: '700000000000000000000003', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
+        req: {sample_id: '400000000000000000000003', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
       });
     });
     it('accepts adding a measurement to the sample of another user for a maintain/admin user', done => {
@@ -487,12 +533,12 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'admin'},
         httpStatus: 200,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
       }).end((err, res) => {
         if (err) return done(err);
-        should(res.body).have.only.keys('_id', 'condition_id', 'values', 'measurement_template');
+        should(res.body).have.only.keys('_id', 'sample_id', 'values', 'measurement_template');
         should(res.body).have.property('_id').be.type('string');
-        should(res.body).have.property('condition_id', '700000000000000000000001');
+        should(res.body).have.property('sample_id', '400000000000000000000001');
         should(res.body).have.property('measurement_template', '300000000000000000000002');
         should(res.body).have.property('values');
         should(res.body.values).have.property('weight %', 0.8);
@@ -506,7 +552,7 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {key: 'janedoe'},
         httpStatus: 401,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
       });
     });
     it('rejects requests from a read user', done => {
@@ -515,7 +561,7 @@ describe('/measurement', () => {
         url: '/measurement/new',
         auth: {basic: 'user'},
         httpStatus: 403,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
       });
     });
     it('rejects unauthorized requests', done => {
@@ -523,7 +569,7 @@ describe('/measurement', () => {
         method: 'post',
         url: '/measurement/new',
         httpStatus: 401,
-        req: {condition_id: '700000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
+        req: {sample_id: '400000000000000000000001', values: {'weight %': 0.8, 'standard deviation': 0.1}, measurement_template: '300000000000000000000002'}
       });
     });
   });
diff --git a/src/routes/measurement.ts b/src/routes/measurement.ts
index b9af125..78b7ec1 100644
--- a/src/routes/measurement.ts
+++ b/src/routes/measurement.ts
@@ -3,6 +3,7 @@ import _ from 'lodash';
 
 import MeasurementModel from '../models/measurement';
 import MeasurementTemplateModel from '../models/measurement_template';
+import SampleModel from '../models/sample';
 import MeasurementValidate from './validate/measurement';
 import IdValidate from './validate/id';
 import res400 from './validate/res400';
@@ -15,11 +16,12 @@ const router = express.Router();
 router.get('/measurement/' + IdValidate.parameter(), (req, res, next) => {
   if (!req.auth(res, ['read', 'write', 'maintain', 'dev', 'admin'], 'all')) return;
 
-  MeasurementModel.findById(req.params.id).lean().exec((err, data) => {
+  MeasurementModel.findById(req.params.id).lean().exec((err, data: any) => {
     if (err) return next(err);
     if (!data) {
       return res.status(404).json({status: 'Not found'});
     }
+    if (data.status ===globals.status.deleted && !req.auth(res, ['maintain', 'admin'], 'all')) return;  // deleted measurements only available for maintain/admin
 
     res.json(MeasurementValidate.output(data));
   });
@@ -37,13 +39,13 @@ router.put('/measurement/' + IdValidate.parameter(), async (req, res, next) => {
     res.status(404).json({status: 'Not found'});
   }
 
-  // add properties needed for conditionIdCheck
+  // add properties needed for sampleIdCheck
   measurement.measurement_template = data.measurement_template;
-  measurement.condition_id = data.condition_id;
-  if (!await conditionIdCheck(measurement, req, res, next)) return;
+  measurement.sample_id = data.sample_id;
+  if (!await sampleIdCheck(measurement, req, res, next)) return;
 
   // check for changes
-  if (measurement.values) {
+  if (measurement.values) {  // fill not changed values from database
     measurement.values = _.assign({}, data.values, measurement.values);
     if (!_.isEqual(measurement.values, data.values)) {
       measurement.status = globals.status.new;  // set status to new
@@ -53,6 +55,7 @@ router.put('/measurement/' + IdValidate.parameter(), async (req, res, next) => {
   if (!await templateCheck(measurement, 'change', res, next)) return;
   await MeasurementModel.findByIdAndUpdate(req.params.id, measurement, {new: true}).lean().exec((err, data) => {
     if (err) return next(err);
+    console.log(data);
     res.json(MeasurementValidate.output(data));
   });
 });
@@ -65,7 +68,7 @@ router.delete('/measurement/' + IdValidate.parameter(), (req, res, next) => {
     if (!data) {
       res.status(404).json({status: 'Not found'});
     }
-    if (!await conditionIdCheck(data, req, res, next)) return;
+    if (!await sampleIdCheck(data, req, res, next)) return;
     await MeasurementModel.findByIdAndUpdate(req.params.id, {status:globals.status.deleted}).lean().exec(err => {
       if (err) return next(err);
       res.json({status: 'OK'});
@@ -79,12 +82,14 @@ router.post('/measurement/new', async (req, res, next) => {
   const {error, value: measurement} = MeasurementValidate.input(req.body, 'new');
   if (error) return res400(error, res);
 
-  if (!await conditionIdCheck(measurement, req, res, next)) return;
-  if (!await templateCheck(measurement, 'new', res, next)) return;
+  if (!await sampleIdCheck(measurement, req, res, next)) return;
+  measurement.values = await templateCheck(measurement, 'new', res, next);
+  if (!measurement.values) return;
 
   measurement.status = 0;
   await new MeasurementModel(measurement).save((err, data) => {
     if (err) return next(err);
+    console.log(data);
     res.json(MeasurementValidate.output(data.toObject()));
   });
 });
@@ -93,25 +98,38 @@ router.post('/measurement/new', async (req, res, next) => {
 module.exports = router;
 
 
-async function conditionIdCheck (measurement, req, res, next) {  // validate condition_id, returns false if invalid  // TODO
-  // const sampleData = await ConditionModel.findById(measurement.condition_id).populate('sample_id').lean().exec().catch(err => {next(err); return false;}) as any;
-  // if (!sampleData) {  // sample_id not found
-  //   res.status(400).json({status: 'Condition id not available'});
+async function sampleIdCheck (measurement, req, res, next) {  // validate sample_id, returns false if invalid or user has no access for this sample
+  const sampleData = await SampleModel.findById(measurement.sample_id).lean().exec().catch(err => {next(err); return false;}) as any;
+  if (!sampleData) {  // sample_id not found
+    res.status(400).json({status: 'Sample id not available'});
     return false
-  // }
-  // if (sampleData.sample_id.user_id.toString() !== req.authDetails.id && !req.auth(res, ['maintain', 'admin'], 'basic')) return false;  // sample does not belong to user
-  // return true;
+  }
+  if (sampleData.user_id.toString() !== req.authDetails.id && !req.auth(res, ['maintain', 'admin'], 'basic')) return false;  // sample does not belong to user
+  return true;
 }
 
-async function templateCheck (measurement, param, res, next) {  // validate measurement_template and values, param for new/change
+async function templateCheck (measurement, param, res, next) {  // validate measurement_template and values, returns values, true if values are {} or false if invalid, param for 'new'/'change'
   const templateData = await MeasurementTemplateModel.findById(measurement.measurement_template).lean().exec().catch(err => {next(err); return false;}) as any;
   if (!templateData) {  // template not found
     res.status(400).json({status: 'Measurement template not available'});
     return false
   }
 
+  // fill not given values for new measurements
+  if (param === 'new') {
+    if (Object.keys(measurement.values).length === 0) {
+      res.status(400).json({status: 'At least one value is required'});
+      return false
+    }
+    const fillValues = {};  // initialize not given values with null
+    templateData.parameters.forEach(parameter => {
+      fillValues[parameter.name] = null;
+    });
+    measurement.values = _.assign({}, fillValues, measurement.values);
+  }
+
   // validate values
-  const {error, value: ignore} = ParametersValidate.input(measurement.values, templateData.parameters, param);
+  const {error, value} = ParametersValidate.input(measurement.values, templateData.parameters, 'null');
   if (error) {res400(error, res); return false;}
-  return true;
+  return value || true;
 }
\ No newline at end of file
diff --git a/src/routes/user.spec.ts b/src/routes/user.spec.ts
index 6a7d69e..a7a2ddb 100644
--- a/src/routes/user.spec.ts
+++ b/src/routes/user.spec.ts
@@ -288,7 +288,7 @@ describe('/user', () => {
         auth: {basic: 'admin'},
         httpStatus: 400,
         req: {pass: 'password'},
-        res: {status: 'Invalid body format', details: '"pass" with value "password" fails to match the required pattern: /^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[!"#%&\'()*+,-.\\/:;<=>?@[\\]^_`{|}~])(?=\\S+$).{8,}$/'}
+        res: {status: 'Invalid body format', details: '"pass" with value "password" fails to match the required pattern: /^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[!"#%&\'()*+,-.\\/:;<=>?@[\\]^_`{|}~])(?=\\S+$)[a-zA-Z0-9!"#%&\'()*+,\\-.\\/:;<=>?@[\\]^_`{|}~]{8,}$/'}
       });
     });
     it('rejects requests from non-admins for another user', done => {
@@ -546,7 +546,7 @@ describe('/user', () => {
         auth: {basic: 'admin'},
         httpStatus: 400,
         req: {email: 'john.doe@bosch.com', name: 'johndoe', pass: 'password', level: 'read', location: 'Rng', device_name: 'Alpha II'},
-        res: {status: 'Invalid body format', details: '"pass" with value "password" fails to match the required pattern: /^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[!"#%&\'()*+,-.\\/:;<=>?@[\\]^_`{|}~])(?=\\S+$).{8,}$/'}
+        res: {status: 'Invalid body format', details: '"pass" with value "password" fails to match the required pattern: /^(?=.*[0-9])(?=.*[a-z])(?=.*[A-Z])(?=.*[!"#%&\'()*+,-.\\/:;<=>?@[\\]^_`{|}~])(?=\\S+$)[a-zA-Z0-9!"#%&\'()*+,\\-.\\/:;<=>?@[\\]^_`{|}~]{8,}$/'}
       });
     });
     it('rejects requests from non-admins', done => {
diff --git a/src/routes/validate/measurement.ts b/src/routes/validate/measurement.ts
index 21b38a2..74c2409 100644
--- a/src/routes/validate/measurement.ts
+++ b/src/routes/validate/measurement.ts
@@ -12,13 +12,14 @@ export default class MeasurementValidate {
           Joi.boolean(),
           Joi.array()
         )
+        .allow(null)
       )
   };
 
   static input (data, param) {  // validate input, set param to 'new' to make all attributes required
     if (param === 'new') {
       return Joi.object({
-        condition_id: IdValidate.get().required(),
+        sample_id: IdValidate.get().required(),
         values: this.measurement.values.required(),
         measurement_template: IdValidate.get().required()
       }).validate(data);
@@ -37,7 +38,7 @@ export default class MeasurementValidate {
     data = IdValidate.stringify(data);
     const {value, error} = Joi.object({
       _id: IdValidate.get(),
-      condition_id: IdValidate.get(),
+      sample_id: IdValidate.get(),
       values: this.measurement.values,
       measurement_template: IdValidate.get()
     }).validate(data, {stripUnknown: true});
diff --git a/src/routes/validate/parameters.ts b/src/routes/validate/parameters.ts
index 79e62ef..e6070b0 100644
--- a/src/routes/validate/parameters.ts
+++ b/src/routes/validate/parameters.ts
@@ -1,7 +1,7 @@
 import Joi from '@hapi/joi';
 
 export default class ParametersValidate {
-  static input (data, parameters, param) {  // data to validate, parameters from template, param: 'new', 'change'
+  static input (data, parameters, param) {  // data to validate, parameters from template, param: 'new', 'change', 'null'(null values are allowed)
     let joiObject = {};
     parameters.forEach(parameter => {
       if (parameter.range.hasOwnProperty('values')) {  // append right validation method according to parameter
@@ -39,6 +39,9 @@ export default class ParametersValidate {
       if (param === 'new') {
         joiObject[parameter.name] = joiObject[parameter.name].required()
       }
+      else if (param === 'null') {
+        joiObject[parameter.name] = joiObject[parameter.name].allow(null)
+      }
     });
     return Joi.object(joiObject).validate(data);
   }
diff --git a/src/routes/validate/template.ts b/src/routes/validate/template.ts
index 6b96a42..111951e 100644
--- a/src/routes/validate/template.ts
+++ b/src/routes/validate/template.ts
@@ -10,7 +10,6 @@ export default class TemplateValidate {
       .min(1),
 
     parameters: Joi.array()
-      .min(1)
       .items(
         Joi.object({
           name: Joi.string()
diff --git a/src/test/db.json b/src/test/db.json
index 7760208..372b09a 100644
--- a/src/test/db.json
+++ b/src/test/db.json
@@ -305,6 +305,27 @@
         "status": 0,
         "measurement_template": {"$oid":"300000000000000000000003"},
         "__v": 0
+      },
+      {
+        "_id": {"$oid":"800000000000000000000004"},
+        "sample_id": {"$oid":"400000000000000000000003"},
+        "values": {
+          "val1": 1
+        },
+        "status": -1,
+        "measurement_template": {"$oid":"300000000000000000000003"},
+        "__v": 0
+      },
+      {
+        "_id": {"$oid":"800000000000000000000005"},
+        "sample_id": {"$oid":"400000000000000000000002"},
+        "values": {
+          "weight %": 0.5,
+          "standard deviation":null
+        },
+        "status": 10,
+        "measurement_template": {"$oid":"300000000000000000000002"},
+        "__v": 0
       }
     ],
     "condition_templates": [