Isotech<\/a> 461 Simple Liquid Nitrogen Apparatus is a compact, safe and economical solution for low\u2011temperature calibration at the boiling point of liquid nitrogen (\u2013195.798 \u00b0C). It provides a practical and lower\u2011cost alternative to the ITL\u2011M\u201118205 while still offering a remarkably stable temperature environment for comparison calibrations under ITS\u201190. The design is intentionally straightforward: a stainless steel dewar, an insulated housing and a metallic equalizing block that holds the thermometers. A split insulated lid reduces evaporation and allows easy replenishment of liquid nitrogen.<\/p>\nSafe and easy to use<\/h3>\n
The 461 operates open to atmosphere, with no internal glass dewar that could implode. This makes the apparatus inherently safe and well suited for routine laboratory use. The only operational requirement is to top up the liquid nitrogen periodically \u2014 typically every 30 minutes \u2014 to maintain the correct level. The dewar has an internal diameter of 100 mm, a depth of 280 mm and a total capacity of about 3 litres. The standard equalizing block accommodates four thermometers up to 8 mm diameter, with a block depth of 120 mm and a total immersion depth of 275 mm.<\/p>\n
Method of operation<\/h3>\n
A calibrated SPRT is placed in the equalizing block alongside the thermometers under test. After the system reaches thermal equilibrium, the liquid level is checked and topped up if necessary. Measurements are typically taken about ten minutes later. The temperature distribution across the block is typically 2 mK, providing an excellent basis for comparison calibrations. Final uncertainties depend on the reference SPRT and any mismatch between the sensors being compared.<\/p>\n
ITS\u201190 considerations<\/h3>\n
Because the apparatus is open to air, a small amount of oxygen will slowly condense, slightly raising the boiling point of nitrogen. This effect is insignificant when a reference SPRT is used and measurements are made with a thermometry bridge such as the microK, which records the ratio between the reference and the test sensor. A comprehensive handbook is supplied, including an article by Henry E. Sostmann explaining the corrections required to relate the calibration to the ITS\u201190 value of the Argon Triple Point.<\/p>\n
Applications<\/h3>\n
The 461 is ideal for laboratories that need:<\/p>\n
\n- > comparison calibrations near \u2013196 \u00b0C,<\/li>\n
- > a simple and safe alternative to more complex cryogenic systems,<\/li>\n
- > a cost\u2011effective method for calibrating SPRTs and industrial PRTs,<\/li>\n
- > a quiet, maintenance\u2011free, bench\u2011mounted solution.<\/li>\n<\/ul>\n
The Isotech 461 Simple Liquid Nitrogen Apparatus delivers a stable, practical and highly economical approach to low\u2011temperature ITS\u201190 comparison calibration. Its simplicity, safety and excellent temperature uniformity make it an excellent choice for laboratories seeking reliable performance without the complexity of advanced cryostats.<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
\n- -196\u00b0C nominal<\/li>\n
- Uncertainty 0.002\u00b0C<\/li>\n
- Safe to use<\/li>\n
- Economical<\/li>\n<\/ul>\n","protected":false},"featured_media":40004,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"_seopress_robots_primary_cat":"none","_seopress_titles_title":"Isotech 461 Simple Liquid Nitrogen Apparatus","_seopress_titles_desc":"The Isotech 461 Simple Liquid Nitrogen Apparatus is a compact, safe and economical solution for low\u2011temperature calibration at the boiling point of liquid","_seopress_robots_index":""},"product_brand":[],"product_cat":[249,263,268],"product_tag":[],"class_list":["post-1871","product","type-product","status-publish","has-post-thumbnail","product_cat-calibration-en","product_cat-temperature-calibration","product_cat-primary-standards","first","instock","shipping-taxable","product-type-simple"],"acf":[],"_links":{"self":[{"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/product\/1871","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/types\/product"}],"replies":[{"embeddable":true,"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/comments?post=1871"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/media\/40004"}],"wp:attachment":[{"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/media?parent=1871"}],"wp:term":[{"taxonomy":"product_brand","embeddable":true,"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/product_brand?post=1871"},{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/product_cat?post=1871"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/calibration.consulting\/en\/wp-json\/wp\/v2\/product_tag?post=1871"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}