Newsletters


Winter 2022

Chairman Notes
Payments for 2022 Enrollment
Data Entry and Reports
Evaluating Laboratory Performance with Magruder Data
Using Control Charts in Quality Assurance
Vendor's Corner
Upcoming Meetings
Magruder Committee Roster



Summer 2022

Chairman Notes
Changing Our Name to Proficiency Testing
Magruder Turns 100!
Upgrade of Lab Portal Website
Value of the Magruder Program in a Regulatory Laboratory
Goals of the International Network on Fertilizer Analysis (INFA)
Vendor's Corner
Magruder Committee Roster
Upcoming Meetings


Winter 2021

Chairman Notes
Investigational Allowance Defined
IA Ratios
Effects of COVID-19 on Sample Shipments
Committee Changes
Upcoming Meetings
Magruder Committee Roster


Summer 2021

Chairman Notes
Investigational Allowances are not Tolerances
Quality Reference Materials
New Sample Schemes Introduced in 2022
Upcoming Meetings