Eisele & Company Certified Clinical Thermometers

Eisele & Company was an American medical-supply maker best known for mid-20th-century clinical (fever) thermometers and accessories. Collectors most often encounter Eisele-marked oral and rectal thermometers in ribbed plastic “pen” cases and pharmacy-imprinted sleeves. This page documents key identifiers, dating tips, and buying considerations for Eisele thermometers.

History & Overview

Eisele & Company operated in the United States during the mid/late 1900s, supplying glass clinical thermometers and related items to pharmacies, hospitals, and distributors. Surviving examples suggest steady production through the post-war decades, with packaging and typography evolving alongside industry trends.

Common Eisele Products

  • Clinical fever thermometers (liquid-in-glass) – 94–108 °F scale, brown/black numerals, fine hash marks.
  • Oral & rectal variants – Long cylindrical “oral” bulbs and stubby “security” bulbs (suitable for rectal or oral use; follow original labeling).
  • Cases & sleeves – Black ribbed plastic pen cases; pharmacy-imprinted sleeves (house-brand packaging with Eisele or OEM stems).

How to Identify an Eisele Thermometer

  • Stem printing: “EISELE” on the back of the scale or near the numeric run; sometimes paired with a compliance mark (e.g., CONN E).
  • Scale: 94–108 °F (occasional 90–108 °F examples), with 0.2 °F ticks and larger whole-degree numerals.
  • Bulb types: Long cylindrical (oral), stubby/security (rectal/oral). Some stems are “flat-type.”
  • Cases: Ribbed black plastic with clip and threaded cap, or pharmacy-imprinted ivory sleeves.

Compliance Marks You May See

U.S. clinical thermometers of the era often include letters indicating conformance to accuracy standards (e.g., CONN E, CONN D). These are not brands; they denote proof testing to a state or laboratory specification current at the time.

Dating Clues (Approximate)

  • Ribbed plastic pen cases: most common from the 1950s–1970s.
  • Flat-type stems & pharmacy sleeves: frequent in 1950s–1960s retail pharmacy stock.
  • Typeface & ink color: later examples trend to cleaner sans-serif numerals and darker inks.

Collector Notes & Buying Guide

  • Completeness: Box + case + certificate increases desirability; loose working examples in good condition remain affordable.
  • Condition: Verify an intact constriction (if present), legible scale, and a straight, unscratched stem. Avoid separated columns.
  • Safety & display: These are vintage mercury devices; handle carefully, store in a protective case, and keep away from children.

Typical Specifications (Eisele examples)

  • Type: Clinical fever thermometer (liquid-in-glass)
  • Scale: 94–108 °F (some 90–108 °F)
  • Bulb Type: Long Cylindrical (Oral) • Stubby/Security (Rectal or Oral) • Flat-type stem variants
  • Case: Ribbed plastic pen case (black) or pharmacy sleeve (ivory)
  • Compliance: Often marked CONN E / CONN D or similar
  • Era: Mid-century (c. 1950s–1970s+)

Gallery

Selected Eisele examples from our collection (oral, rectal, flat-type, and case variations).

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