Section 12 – Milk Analysis - Revision history

Aashish: /* Verification/adjustment of calibration settings */

2024-09-04T14:02:34Z

Verification/adjustment of calibration settings

← Older revision		Revision as of 14:02, 4 September 2024
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	For that, calculate the standard deviation of ''b'':[[File:Imagefor.png\|none\|thumb]] (8)		For that, calculate the standard deviation of ''b'':[[File:Imagefor.png\|none\|thumb]] (8)
			with[[File:Imagewith.png\|none\|thumb]]
	with[[File:Imagewith.png\|none\|thumb]] (9)		(9) Applying a 95% confidence interval, the current slope is still correct if:[[File:Imageby.png\|none\|thumb]] (10)

	Applying a 95% confidence interval, the current slope is still correct if:[[File:Imageby.png\|none\|thumb]] (10)

	where ''t<sub>0.975</sub>'' is the 0,975 quantile of the Student distribution with q-2 degrees of freedom.		where ''t<sub>0.975</sub>'' is the 0,975 quantile of the Student distribution with q-2 degrees of freedom.
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	The mean bias is still correct if in agreement with:[[File:Imagewith2.png\|none\|thumb]] (12)		The mean bias is still correct if in agreement with:[[File:Imagewith2.png\|none\|thumb]] (12)

	where ''t<sub>0,975</sub>'' is the 0,975 quantile of the Student distribution with ''q-2'' degrees of freedom and ȳ(xbar) being the predicted value from [[File:Imagefrom.png\|none\|thumb\|161x161px]]		where ''t<sub>0,975</sub>'' is the 0,975 quantile of the Student distribution with ''q-2'' degrees of freedom and ȳ(xbar) being the predicted value from [[File:Imagefrom.png\|none\|thumb\|161x161px]]

	If both the test for slope and mean bias are negative, ''a'' does not statistically differ from ''a<sub>c</sub>'' if[[File:Imageboth.png\|none\|thumb]] (13)		If both the test for slope and mean bias are negative, ''a'' does not statistically differ from ''a<sub>c</sub>'' if[[File:Imageboth.png\|none\|thumb]] (13)

	with[[File:Imagewith3.png\|none\|thumb]] (14)		with[[File:Imagewith3.png\|none\|thumb]] (14)

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	b. Calculate for each pairwise measurement the difference ''E<sub>i</sub>'' between the two results:[[File:Imagewithe.png\|none\|thumb]] (18)		b. Calculate for each pairwise measurement the difference ''E<sub>i</sub>'' between the two results:[[File:Imagewithe.png\|none\|thumb]] (18)

	c. Assuming additivity of bias for about equal SCC values, the reference value for the SRM, ''x<sub>SRM</sub>'', can now be calculated:[[File:Imagewithf.png\|none\|thumb]] (19)		c. Assuming additivity of bias for about equal SCC values, the reference value for the SRM, ''x<sub>SRM</sub>'', can now be calculated:[[File:Imagewithf.png\|none\|thumb]] (19)

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	''C<sub>crm</sub>'' is the reference value of the (mixed) CRM and (20)[[File:Imagewithg.png\|none\|thumb]]d. The standard uncertainty with the reference value for the SRM, ''u<sub>SRM</sub>'', is:[[File:Imagewithh.png\|none\|thumb]] (21)		''C<sub>crm</sub>'' is the reference value of the (mixed) CRM and (20)[[File:Imagewithg.png\|none\|thumb]]d. The standard uncertainty with the reference value for the SRM, ''u<sub>SRM</sub>'', is:[[File:Imagewithh.png\|none\|thumb]] (21)

	with ''u<sub>CRM</sub>'' being the standard uncertainty of the value carried by the CRM and[[File:Imagewithi.png\|none\|thumb]] (22)		with ''u<sub>CRM</sub>'' being the standard uncertainty of the value carried by the CRM and[[File:Imagewithi.png\|none\|thumb]] (22)

Aashish: /* Assigning reference values to Secondary Reference Material (SRM) */

2024-09-04T14:00:27Z

Assigning reference values to Secondary Reference Material (SRM)

← Older revision		Revision as of 14:00, 4 September 2024
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	The uncertainty of the mixed CRM material, umixed CRM, can be calculated from:[[File:Imageupload.png\|none\|thumb\|539x539px]] (17)		The uncertainty of the mixed CRM material, umixed CRM, can be calculated from:[[File:Imageupload.png\|none\|thumb\|539x539px]] (17)
			with[[File:Imagewith4.png\|thumb\|124x124px\|none]] = uncertainty with the certified value for CRM ERM<sup>®</sup>-BD001a

	~~with~~[[File:~~Imagewith4~~.png~~\|left~~\|thumb\|~~124x124px]] = uncertainty with the certified value for CRM ERM<sup>®</sup>-BD001a~~		[[File:Imagewithb.png\|thumb\|none]] = uncertainty with the certified value for CRM ERM<sup>®</sup>-BD001b

	~~[[File:Imagewithb.png\|left\|thumb~~]] = uncertainty with the certified value for CRM ERM<sup>®</sup>-BD001b



	[[File:Imagewithc.png\|~~left~~\|~~thumb~~]]= volume fraction of CRM ERM<sup>®</sup>-BD001a in the mixed sample		[[File:Imagewithc.png\|thumb\|none]]= volume fraction of CRM ERM<sup>®</sup>-BD001a in the mixed sample



	[[File:Imagewithd.png\|~~left~~\|~~thumb~~]]= volume fraction of CRM ERM<sup>®</sup>-BD001b in the mixed sample		[[File:Imagewithd.png\|thumb\|none]]= volume fraction of CRM ERM<sup>®</sup>-BD001b in the mixed sample

Aashish: /* Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk */

2024-08-30T03:09:02Z

Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk

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Aashish: /* Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk */

2024-08-30T02:57:37Z

Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk

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Aashish: /* Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk */

2024-08-28T13:25:02Z

Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk

← Older revision		Revision as of 13:25, 28 August 2024
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	= Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk =		= Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk =
			<div class="mw-collapsible mw-collapsed">
			<div>
	== Background ==		== Background ==
	Milk somatic cell count (SCC) is a widely used indicator for monitoring the udder health of several mammalian species and is relevant in food hygiene regulations, milk payment testing, farm management and breeding programmes [3]. In February 2020, the European Commission Joint Research Centre (EC JRC) launched a new certified reference material (CRM ERM<sup>®</sup>-BD001) for somatic cell counting in milk. The launch is one of the tangible outcomes of a close cooperation between the International Dairy Federation (IDF), the International Committee for Animal Recording (ICAR) and EC JRC in developing solutions and tools to promote a better global equivalence in somatic cell counting in milk.		Milk somatic cell count (SCC) is a widely used indicator for monitoring the udder health of several mammalian species and is relevant in food hygiene regulations, milk payment testing, farm management and breeding programmes [3]. In February 2020, the European Commission Joint Research Centre (EC JRC) launched a new certified reference material (CRM ERM<sup>®</sup>-BD001) for somatic cell counting in milk. The launch is one of the tangible outcomes of a close cooperation between the International Dairy Federation (IDF), the International Committee for Animal Recording (ICAR) and EC JRC in developing solutions and tools to promote a better global equivalence in somatic cell counting in milk.
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	* Silvia Orlandini, International Committee on Animal Recording, The Netherlands, silvia@icar.org		* Silvia Orlandini, International Committee on Animal Recording, The Netherlands, silvia@icar.org
	* Werner Luginbühl, ChemStat, Switzerland, info@chemstat.ch		* Werner Luginbühl, ChemStat, Switzerland, info@chemstat.ch
			</div>
			</div>

Aashish: /* Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk */

2024-08-28T13:24:13Z

Procedure 2: Guidance on application of EC JRC Certified Reference Material for SCC in milk

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Aashish: /* Assessment of overall accuracy: Example for fat */

2024-08-28T13:21:26Z

Assessment of overall accuracy: Example for fat

← Older revision		Revision as of 13:21, 28 August 2024
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	[[File:Imagemy6.png\|center\|thumb\|449x449px]]		[[File:Imagemy6.png\|center\|thumb\|449x449px]]
	[[File:Imagemy7.png\|center\|thumb\|466x466px]]		[[File:Imagemy7.png\|center\|thumb\|466x466px]]
			</div>
	</div>		</div>

Aashish at 12:33, 28 August 2024

2024-08-28T12:33:53Z

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Aashish: /* Assessment of linearity: Example of a somatic cell counter (cf. IDF 148) */

2024-08-28T12:32:14Z

Assessment of linearity: Example of a somatic cell counter (cf. IDF 148)

← Older revision		Revision as of 12:32, 28 August 2024
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	<center>		<center>
	{\| class="wikitable" style="text-align: center;"		{\| class="wikitable" style="text-align: center;"
	\|Polynome		\|'''Polynome'''
	\|b3		\|'''b3'''
	\|b2		\|'''b2'''
	\|b1		\|'''b1'''
	\|a		\|'''a'''
	\|-		\|-
	\|Degree 3		\|'''Degree 3'''
	\|<nowiki>-0,000256</nowiki>		\|<nowiki>-0,000256</nowiki>
	\|0,019324		\|0,019324
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	\|13,063507		\|13,063507
	\|-		\|-
	\|Degree 2		\|'''Degree 2'''
	\|		\|
	\|<nowiki>-0,019194</nowiki>		\|<nowiki>-0,019194</nowiki>
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	\|1,847156		\|1,847156
	\|-		\|-
	\|Degree 1		\|'''Degree 1'''
	\|		\|
	\|		\|
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	\|}		\|}
	{\| class="wikitable"		{\| class="wikitable"
	\|Polynome		\|'''Polynome'''
	\|Sy,xk		\|'''Sy,xk'''
	\|d.f.		\|'''d.f.'''
	\|Sy,xk/Sy,x3		\|'''Sy,xk/Sy,x3'''
	\|F0,95		\|'''F0,95'''
	\|Limit		\|'''Limit'''
	\|Sy,xk/Sy,x2		\|'''Sy,xk/Sy,x2'''
	\|F0,95		\|'''F0,95'''
	\|Limit		\|'''Limit'''
	\|-		\|-
	\|degree 3		\|'''degree 3'''
	\|7,78		\|7,78
	\|17		\|17
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	\|		\|
	\|-		\|-
	\|degree 2		\|'''degree 2'''
	\|9,63		\|9,63
	\|18		\|18
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	\|		\|
	\|-		\|-
	\|degree 1		\|'''degree 1'''
	\|18,96		\|18,96
	\|19		\|19

Aashish: /* Assessment of linearity: Example of a somatic cell counter (cf. IDF 148) */

2024-08-28T12:31:15Z

Assessment of linearity: Example of a somatic cell counter (cf. IDF 148)

← Older revision		Revision as of 12:31, 28 August 2024
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	k1 = k-1, k2 = q-k-1 and a risk of error.		k1 = k-1, k2 = q-k-1 and a risk of error.
			<center>
	{\| class="wikitable"		{\| class="wikitable" style="text-align: center;"
	\|'''Mean'''		\|'''Mean'''

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	35		35
	\|}		\|}
	{\| class="wikitable"		</center>
			<center>
			{\| class="wikitable" style="text-align: center;"
	\|Polynome		\|Polynome
	\|b3		\|b3
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	\|1,09		\|1,09
	\|}		\|}
			</center>

	'''Note'''		'''Note'''
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	[[File:Imagemy3.png\|center\|thumb\|429x429px]]		[[File:Imagemy3.png\|center\|thumb\|429x429px]]
	[[File:Imagemy5.png\|center\|thumb\|433x433px]]		[[File:Imagemy5.png\|center\|thumb\|433x433px]]


	=== Assessment of overall accuracy: Example for fat ===		=== Assessment of overall accuracy: Example for fat ===

← Older revision		Revision as of 14:02, 4 September 2024
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	For that, calculate the standard deviation of ''b'':[[File:Imagefor.png\|none\|thumb]] (8)		For that, calculate the standard deviation of ''b'':[[File:Imagefor.png\|none\|thumb]] (8)
			with[[File:Imagewith.png\|none\|thumb]]
	with[[File:Imagewith.png\|none\|thumb]] (9)		(9) Applying a 95% confidence interval, the current slope is still correct if:[[File:Imageby.png\|none\|thumb]] (10)

	Applying a 95% confidence interval, the current slope is still correct if:[[File:Imageby.png\|none\|thumb]] (10)

	where ''t<sub>0.975</sub>'' is the 0,975 quantile of the Student distribution with q-2 degrees of freedom.		where ''t<sub>0.975</sub>'' is the 0,975 quantile of the Student distribution with q-2 degrees of freedom.
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	The mean bias is still correct if in agreement with:[[File:Imagewith2.png\|none\|thumb]] (12)		The mean bias is still correct if in agreement with:[[File:Imagewith2.png\|none\|thumb]] (12)

	where ''t<sub>0,975</sub>'' is the 0,975 quantile of the Student distribution with ''q-2'' degrees of freedom and ȳ(xbar) being the predicted value from [[File:Imagefrom.png\|none\|thumb\|161x161px]]		where ''t<sub>0,975</sub>'' is the 0,975 quantile of the Student distribution with ''q-2'' degrees of freedom and ȳ(xbar) being the predicted value from [[File:Imagefrom.png\|none\|thumb\|161x161px]]

	If both the test for slope and mean bias are negative, ''a'' does not statistically differ from ''a<sub>c</sub>'' if[[File:Imageboth.png\|none\|thumb]] (13)		If both the test for slope and mean bias are negative, ''a'' does not statistically differ from ''a<sub>c</sub>'' if[[File:Imageboth.png\|none\|thumb]] (13)

	with[[File:Imagewith3.png\|none\|thumb]] (14)		with[[File:Imagewith3.png\|none\|thumb]] (14)

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	b. Calculate for each pairwise measurement the difference ''E<sub>i</sub>'' between the two results:[[File:Imagewithe.png\|none\|thumb]] (18)		b. Calculate for each pairwise measurement the difference ''E<sub>i</sub>'' between the two results:[[File:Imagewithe.png\|none\|thumb]] (18)

	c. Assuming additivity of bias for about equal SCC values, the reference value for the SRM, ''x<sub>SRM</sub>'', can now be calculated:[[File:Imagewithf.png\|none\|thumb]] (19)		c. Assuming additivity of bias for about equal SCC values, the reference value for the SRM, ''x<sub>SRM</sub>'', can now be calculated:[[File:Imagewithf.png\|none\|thumb]] (19)

Line 3,484:		Line 3,479:

	''C<sub>crm</sub>'' is the reference value of the (mixed) CRM and (20)[[File:Imagewithg.png\|none\|thumb]]d. The standard uncertainty with the reference value for the SRM, ''u<sub>SRM</sub>'', is:[[File:Imagewithh.png\|none\|thumb]] (21)		''C<sub>crm</sub>'' is the reference value of the (mixed) CRM and (20)[[File:Imagewithg.png\|none\|thumb]]d. The standard uncertainty with the reference value for the SRM, ''u<sub>SRM</sub>'', is:[[File:Imagewithh.png\|none\|thumb]] (21)

	with ''u<sub>CRM</sub>'' being the standard uncertainty of the value carried by the CRM and[[File:Imagewithi.png\|none\|thumb]] (22)		with ''u<sub>CRM</sub>'' being the standard uncertainty of the value carried by the CRM and[[File:Imagewithi.png\|none\|thumb]] (22)

← Older revision		Revision as of 14:00, 4 September 2024
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	The uncertainty of the mixed CRM material, umixed CRM, can be calculated from:[[File:Imageupload.png\|none\|thumb\|539x539px]] (17)		The uncertainty of the mixed CRM material, umixed CRM, can be calculated from:[[File:Imageupload.png\|none\|thumb\|539x539px]] (17)
			with[[File:Imagewith4.png\|thumb\|124x124px\|none]] = uncertainty with the certified value for CRM ERM<sup>®</sup>-BD001a

	~~with~~[[File:~~Imagewith4~~.png~~\|left~~\|thumb\|~~124x124px]] = uncertainty with the certified value for CRM ERM<sup>®</sup>-BD001a~~		[[File:Imagewithb.png\|thumb\|none]] = uncertainty with the certified value for CRM ERM<sup>®</sup>-BD001b

	~~[[File:Imagewithb.png\|left\|thumb~~]] = uncertainty with the certified value for CRM ERM<sup>®</sup>-BD001b



	[[File:Imagewithc.png\|~~left~~\|~~thumb~~]]= volume fraction of CRM ERM<sup>®</sup>-BD001a in the mixed sample		[[File:Imagewithc.png\|thumb\|none]]= volume fraction of CRM ERM<sup>®</sup>-BD001a in the mixed sample



	[[File:Imagewithd.png\|~~left~~\|~~thumb~~]]= volume fraction of CRM ERM<sup>®</sup>-BD001b in the mixed sample		[[File:Imagewithd.png\|thumb\|none]]= volume fraction of CRM ERM<sup>®</sup>-BD001b in the mixed sample