A generally known procedure for photometric analysis of a substance uses a container called a cuvet made to have predetermined optical properties. A measured quantity of a reagent liquid is placed in the cuvet, and a precisely measured amount of the test substance is added to and mixed with the reagent liquid so that the test substance and the reagent liquid are exactly in a predetermined ratio to insure accuracy of the test. Then the cuvet is mounted in an analyzing appliance such as a photometer where light is directed through the cuvet and the reagent liquid containing the test substance for measuring the light permeability of the contents of the cuvet to analyze a property of the test substance. Cuvets are made in different sizes and of different materials, reagent liquids vary for different tests to be made, and different ratios of test substances to reagent liquids are used, depending on the materials involved. Photometric light transmittance tests can be made with ultra-violet or visible light, and measurement of light scattering and other optical effects can also be made by using cuvets.
Some photometric tests using cuvets are made for medical purposes, and one such test involves measuring the hemoglobin in human blood. Suitable reagent liquids and general test procedures are well known for measuring hemoglobin in the blood and for other medical and non-medical tests using cuvets.
The invention involves recognition of ways that prior art methods of preparing cuvets for test analyses are cumbersome, slow, and lead to inaccuracies unless great care is taken in accurately measuring the reagent liquid and the test substance to achieve the precise ratio desired between these materials. Especially for medical tests, which often have to be made speedily because a patient's condition requires prompt action after an accident or before some urgent operation, speedy and accurate cuvet preparation is highly desirable. The urgency in preparing a cuvet quickly during a medical emergency can easily lead to inaccuracy.
The invention also involves recognition of a way that a cuvet can be prepared speedily and easily with high and reliable accuracy using simple and convenient materials. The invention aims at speed and accuracy in cuvet preparation using relatively inexpensive materials.