3 - Calibration standards and specimens - Agar Scientific
3 - Calibration standards and specimens - Agar Scientific
3 - Calibration standards and specimens - Agar Scientific
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<strong>Calibration</strong> <strong>st<strong>and</strong>ards</strong> <strong>and</strong> <strong>specimens</strong><br />
NPL image analysis st<strong>and</strong>ard<br />
This high precision st<strong>and</strong>ard is designed for calibrating image analysis systems <strong>and</strong> identifying deviations <strong>and</strong> distortions in optical imaging<br />
equipment. The 75 x 25 mm slide has a series of grid patterns of known edge length which can be used for precision measurement.<br />
A mono size array of 15 µm spots is used to check image distortion. A root-2 progression of spots from 3 to 48 µm allows threshold<br />
levels <strong>and</strong> resolution to be checked. Using the log- normal distribution array of 100 spots, the mean <strong>and</strong> st<strong>and</strong>ard deviation of the spot<br />
sizes can be determined <strong>and</strong> compared with the certified values. It is supplied with recommendations for use <strong>and</strong> an individual NPL<br />
certificate of calibration.<br />
There are four test areas (see image):<br />
1. 400 x 400 µm square grid sub-divided into 200, 100, 50 <strong>and</strong> 25 µm squares which can be used to detect gross image distortions <strong>and</strong><br />
as an accurate two dimensional stage micrometer.<br />
2. 20 x 17 array of nominally 15 µm diameter dots can be used to identify lens distortions.<br />
3. Root-2 array of spots from 3 to 48 µm in diameter for determining the threshold level of cameras <strong>and</strong> microscope systems.<br />
4. Log-normal distribution array of 100 spots ranging from 4.5 to 27 µm in diameter enables the mean <strong>and</strong> st<strong>and</strong>ard<br />
deviation of the spot size to be determined <strong>and</strong> compared with certified values.<br />
S1918<br />
Image analysis st<strong>and</strong>ard, certified<br />
Micro-Ruler MR-1<br />
A traceable ruler for magnification verification is an essential part of many quality control programmes. The Micro-Ruler MR-1 is a metric<br />
dimensional calibration product to fulfil this purpose. One significant use of the MR-1 is to measure magnified images to determine absolute<br />
magnification.<br />
The MR-1 ruler is manufactured using accurate semiconductor fabrication equipment. The pattern is anti-reflective chromium over soda lime<br />
glass. The overall size is 180 x 25 x 3 mm <strong>and</strong> it is labelled in millimetres, with the scale extending over 150 mm with 0.01 mm increments.<br />
The linear expansion coefficient is 9 x 10 -6 ppm/°C <strong>and</strong>, over its full 150 mm length, the ruler could change dimensions by 1.35 µm/°C. It<br />
has been designed to be viewed from either side, as the markings are both right-reading <strong>and</strong> mirror images, allowing the ruler markings to<br />
be placed in direct contact with the sample <strong>and</strong> avoiding parallax errors. The ruler uncertainty is ± 0.5 µm over 0 to 10 mm length <strong>and</strong><br />
± 2.5 µm over the entire 150 mm length.<br />
The ruler also has circles <strong>and</strong> squares of 0.02, 0.05, 0.10, 0.50, 1.00, 2.00 <strong>and</strong> 5.00 mm diameter <strong>and</strong> side length.<br />
We offer the MR-1 only as a certified traceable reference st<strong>and</strong>ard <strong>and</strong> recommend recertification at five yearly intervals.<br />
L4520<br />
Micro-Ruler MR-1, certified<br />
Tel: +44 (0)1279 813519 Fax: +44 (0)1279 815106 Email: sales@agarscientific.com www.agarscientific.com 42