This product is isolated and purified from the herbs of Laggera pterodonta
Soluble in Chloroform,Dichloromethane,Ethyl Acetate,DMSO,Acetone,etc.
473.1±45.0 °C at 760 mmHg
HS Code Reference
Personal Projective Equipment
For Reference Standard and R&D, Not for Human Use Directly.
provides coniferyl ferulate(CAS#:64165-98-6) MSDS, density, melting point, boiling point, structure, formula, molecular weight etc. Articles of coniferyl ferulate are included as well.>> amp version: coniferyl ferulate
PURPOSE: Eduard Jaeger’s original Test-Types were carefully evaluated: (1) to determine whether Jaeger had maintained a consistent standard, (2) to establish the correct Snellen equivalent for Jaeger’s Test-Types, (3) to answer the question of why and how the standard was lost, and (4) to compare the visual angle of optotypes to lines of continuous text. METHODS: All original Viennese editions of Jaeger’s Test-Types, as well as first generation United Kingdom (UK) and United States (US) versions, were evaluated. Data were collected objectively using a microruler with a 20X loupe and subjectively using a laser distance-measuring device. The data were analyzed using Microsoft Excel. All previous measurements of Jaeger’s Test-Types, objective and subjective, collected over the past 133 years were compared to the current data and to each other. RESULTS: The correct Snellen equivalent of Jaeger’s Test-Types was determined. The visual angle created from the measurement of the height of lowercase letters, without ascenders or descenders, provides an accurate method of assigning a visual angle of a line of continuous text. Comparing the typefaces used in printing first generation UK and US versions of Jaeger’s Test-Types to the Viennese editions provided an explanation for the absence of a consistent standard for Jaeger’s Test-Types today. CONCLUSIONS: All 10 versions of Jaeger’s original Test-Types are virtually identical and established a gold standard for reading vision tests. Jaeger’s standard was lost when his Test-Types were first printed in the UK and the US using local typefaces. The Jaeger standard has been re-established. Visual angles determined using continuous text are comparable to those obtained by using optotypes.
Eduard Jaeger's Test-Types (Schrift-Scalen) and the historical development of vision tests.
P E Runge
Abstracts from the 51st European Society of Human Genetics Conference: Posters