hemoglobinometer

A hemoglobinometer is a device designed to measure the concentration of hemoglobin in a blood sample, typically reported as grams of hemoglobin per deciliter of blood (g/dL). Hemoglobin concentration is a key parameter in evaluating anemia, hydration status, and overall oxygen-carrying capacity. Hemoglobinometers range from simple field devices to automated laboratory instruments.

Most modern hemoglobinometers operate on photometric principles. A blood sample is treated with a reagent to form a colored species whose light absorbance at specific wavelengths is proportional to Hb concentration. The instrument converts absorbance to Hb concentration and displays the result. The cyanmethemoglobin method (Drabkin's reagent) is a common reference technique; alternatives include Sahli's method and azide methods used in some point-of-care devices.

Device types include handheld portable meters with disposable cuvettes or microplates, compact bedside units, and larger benchtop analyzers in clinical laboratories. Some devices provide noninvasive estimates by spectroscopy of a fingertip, but such readings are typically less precise and may require calibration.

Applications include anemia screening, preoperative evaluation, blood donor certification, and routine monitoring in clinics and field settings. Hemoglobinometers are valued for speed, small blood volume requirements, and ease of use; however, results should be interpreted with consideration of hematocrit, sample quality, and instrument calibration.

Limitations include potential interference by lipids or abnormal hemoglobins, sample hemolysis, recent transfusions, or high leukocyte counts. Reagent stability, temperature, and device calibration affect accuracy. In laboratory practice, the cyanmethemoglobin method remains the reference standard, while point-of-care devices provide approximate results.