A metal instrument with a round grey base that supports a rectangular metal enclosure. Above the instrument, and midway down the support between the base and the enclosure, are open, circular ports that connect through the body of the enclosure.
On one narrow face of the enclosure is a large dial reading in volume % between 0 and 3. On the opposite face is a silver knob.
Accession Number: 2025.sk.21
Alternative Name:
Primary Materials:
A large black and white label fixed to the one broad face of the instrument reads: “DONATED BY// MR.G.G.WHITTAKER”
A contact label for Benson Medical Products Ltd., located in Markham, Ontario, is pasted to the lower left of the same face.
On the opposite broad face is a bright yellow/ orange warning label. This reads “THE USE OF The NARKOTEST-M FOR THE// MEASUREMENT OF INSPIRATORY OR EXPIRATORY// CONCENTRATION DOES NOT ELIMINATE THE NEED// FOR CLINICAL OBSERVATION.// DO NOT CLEAN WITH LIQUID DISINFECTION// SOLUTIONS. AFTER A FULL DAY’S USE REMOVE FROM// THE APPARATUS AND ALLOW TO DRY OVERNIGHT IN// NORMAL ROOM CONDITIONS.”
A maker’s label is affixed to the narrow rear face.
Dimensions (cm): Height = 32, Width = 18, Length = 14.
The Narkotest-M instrument is used in an anesthetic circuit to measure the concentration of anesthetic gas as a percentage of the gas flow.
The operating mechanism is described as follows in White and Wardley-Smith 1972:
“Gas passes over lightly tensioned silicone rubber strips which are connected to the pointer by a lever system. Anaesthetic agents are highly soluble in the silicone rubber which dissolves the agent from the gas passing over it. A change in elasticity is produced which results in a movement of the pointer. A zero adjustment control is provided on the back of the instrument.”
The instrument compensates for temperature using a bimetalic strip and is accurate between 15 ° and 35 °C.
Simplified diagram of the Narkotest operating mechanism (White and Wardley-Smith 1972, 1101)
Condition:
Associated Instruments:
Drägerwerk AG & Co. KGaA, Lübeck, Germany.
Date of Manufacture: c. 1970s
Provenance:
Harry J. Lowe, and Karl Hagler (1971) “Clinical and Laboratory Evaluation of an Expired Anesthetic Gas Monitor (Narko-Test).” Anesthesiology (Philadelphia) 34, no. 4: 378–82.
D. C. White and Bridget Wardley-Smith (1972). “THE ‘NARKOTEST’ ANAESTHETIC GAS METER.” British Journal of Anaesthesia 44, no. 10: 1100–1104.
Historical Notes: