'Specific gravity' is a function of the number, density and weight of the solute particles present in the urine, and is used as a measure of the concentrating power of the kidney. Specific gravity continues to be the most common unit for reporting total solids concentration. Rudinsky AJ, Wellman M, Tracy G, Stoltenberg L, DiBartola SP, Chew DJ. Intraclass correlations between reagent strips or hydrometry and refractometry ranged from low to moderate. disadvantages: This test requires the collection of urine (which is sometimes difficult) and the purchase of a This may reflect tester subjectivity and the difficulty in determining the density-indicating meniscus. However, the measurement is affected by alcohol, and the Final Gravity reading needs to be corrected Continue reading Refractometer measures the urine density on the basis of the index of light refraction. It might not always yield to accurate result as urine test using a test strip is time-sensitive. However, the correlation coefficient decreased as the urine specific gravity increased. If it is for a routine urinalysis, the patient is allowed to eat and drink the usual way. National Collegiate Athletic Association Wrestling Rules Committee. A urine test strip is more of qualitative and not much on the quantitative information. McCrossin and Roy12 and Adams16 reported correlation coefficients of r = .82 and r = .80, respectively, between reagent strips and refractometry and concluded that the reagent strips were not a valid measure of urine specific gravity. View in full-text. It was calibrated with distilled water before use. A spectrophotometer is a machine used to determine the absorbance of light at any given wavelength. If you have a specific gravity of urine under 1.030, it means you are still within the normal range. Refractometer Clinical Refractometer measures urine specific gravity, or gives the refractive index in seconds. Finally, Dorizzi and Caputo18 compared 2 different reagent strips with refractometry in 1725 urine samples from hospital inpatients and outpatients and reported correlation coefficients of only r = .663 and r = .514. Each refractometer pair was compared using Spearman's rank correlation, Bland-Altman difference plots, and Deming regression analyses. 1 What are the advantages of using a refractometer instead of other specific gravity measurement equipment used in clinical microscopy? PMC A false negative was defined as a measurement by the hydrometer or reagent strip indicating euhydration (value did not exceed 1.020), when the refractometer indicated dehydration (value exceeded 1.020). Substances are put into cuvettes that are glass or quartz containers that light can easily travel through. Identify possible causes for abnormal specific gravities of urine. WebRefractometric anaylsis of the urine of patients and athletes quickly shows vital human health parameters such as urine specific gravity, urine total solids and urine osmotic pressure. Refractometers showed reporting bias compared with the Brix solutions used as a reference standard for urine. First, place an empty graduated cylinder on a balance, determine its mass and record the value under the Density of Water: Data Table. For generating valuable data with a desired accuracy and to quantify concentration of the constituents present in the samples being analyzed. For example, if the urine specimen was collected by an untrained collector in an unprofessional setting. Refractometer. Before Refractometer: determines the concentration of the dissolved particles in the specimen by measuring the refractive index. Advantages are, only one or two drops of urine is sufficient and temperature correction not necessary. ii. Rowe JC, Hokamp JA, Braatz JN, Freitag-Engstrom JR, Stephens NL, Chew DJ, Langston C, Rudinsky AJ. Tvedten HW, Ouchterlony H, Lilliehk IE. Urine specific gravity measurements: comparison of a new reagent strip method with existing methodologies, as applied to the water concentration/dilution tests. As weights are added one by one to the scales, water can be added to the tank so that the hydrostatic force balances the weights and bring the arm back to horizontal. WebThe refractometer is reliable, fast, accurate, and technically easy to use and requires only a single drop of urine. The .gov means its official. In a routine urinalysis, the urine is checked for its appearance, concentration, and composition. We calculated a 3 2 4 (method trial tester) repeated-measures analysis of variance for significant mean differences in urine specific-gravity measurements among methods, trials, and testers with alpha set at P < .05 and followed up with Scheff post hoc comparisons. Easy to operate - Simply read the instructions that accompany the refractometer. Intraclass reliability between trials was high for refractometry (R = .998) and hydrometry (R = .987) and moderate for reagent strips (R = .854). Intraclass coefficients between refractometry and hydrometry were moderate (R = .869) and low between refractometry and reagent strips (R = .573). 7 How specific is urine specific gravity? However, if you are going to perform other tests along with urinalysis, then you might be required to undergo fasting for a particular period of time. Urine-based testing can be challenged if the collection standards are not followed. 19981999 wrestling weight certification program. Comparison of specific gravity analysis of feline and canine urine, using five refractometers, to pycnometric analysis and total solids by drying. The urinometer is an laboratory material that normally used to measure the specific gravity of urine . Chapter 4 Flashcards | Quizlet Measuring urine S.G. A refractometer is an instrument that measures the refractive index of a liquid. I will be doing this experiment to understand density of water compared to the volume of an object. Federal government websites often end in .gov or .mil. WebRefractometers are designed for specific operations, such as measuring liquids such as oils, or water-based liquids, gases, and transparent or translucent solids, such as gemstones. Bland-Altman plot for refractometry and hydrometry. WebSaline Refractometer is the way to go. It checks for chemical substances that might be present in urine, which aids in checking the persons health condition, urine concentration, and the existence of a particular disease. If you want to be more precise with your measurements, therefore achieving better brews, then you might want to invest in a refractometer. A refractometer can be affected by particle size, temperature, and concentration of the solution as well as light wavelength. If you are not going to analyze the result immediately, then the changes in the color of the strip yields to an inaccurate results. Gounden and Newall14 compared results using reagent strips with 2 refractometers in 12 normal subjects and reported correlations of .906 and .911. It does this by using a source of white light through a prism, which gives multiple wavelengths that can be individually focused (Ayyagari and Nigam, 2007). Refractometer vs. Hydrometer Pros and Cons - Homebrew Talk document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); 2022 LaboratoryInfo.com. A comparison of reagent strips and the refractometer for Casa DJ, Armstrong LE, Hillman SK, et al. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. This cookie is set by GDPR Cookie Consent plugin. 10 microliters of the sample is then added and the assay absorption is measured at 340nm. The subjects provided written informed consent, and the study was approved by the institution's institutional review board. COMPARISON OF URINARY OSMOMETER AND REFRACTOMETER Bland JM, Altman DG. It is a ratio of the velocity of light in air to the velocity of light in solution, and is directly proportional to the number of dissolved solids in urine. 19992000 Wrestling weight certification program. One is an optical refractometer in which a liquid sample is placed on one end. Is there a digital hydrometer? - coalitionbrewing.com National Library of Medicine advantages of refractometer compared to urinometer. If the specimen is cold, 0.001 must be subtracted from the reading for every 3 degreeC that the specimen temperature is below the urinometer calibration temperature.Conversely, 0.001 must be added to the reading for every 3degreeC that the advantages of refractometer compared to urinometer. Joined Sep 10, 2011 Messages 1,241 Reaction score 66 Location Austin. Some manufacturers have a specific gravity correction factor for high protein and glucose What are 6 of Charles Dickens classic novels? Vet Clin Pathol. Most refractometers use a prism and a light source to illuminate the sample. Method Trial Tester Interaction (Mean SD). cinma orlans : programme. State the principle of the chemical dipstick test for leukocytes 35. 2001 Apr;16(4):374-82. doi: 10.1007/s004670000551. Refractometer measurements are commonly made using the Pulfrich or ABBE refractometer design. Comparison of 3 Methods to Assess Urine Specific Gravity in Method and Trial Main Effects (Mean SD). Please enable it to take advantage of the complete set of features! It only shows limited information about the composition of urine. In contrast, other researchers12,1619 assessing the validity of reagent strips with refractometry have reported that the reagent strips are not an acceptable alternative to refractometry. Urine samples were collected between 1:00 PM and 3:00 PM Greenwich Mean Time and analyzed immediately. government site. The more particles there are in a liquid the more a beam of light will be bent (refracted) as it passes from one medium to another e.g. WebTo prepare a solution appropriate for quality control of the refractometer, a technician should use: A. urea with a specific gravity of 1.040 B. water with a specific gravity of 1.005 C. sodium chloride with a specific gravity of 1.022 D. calcium chloride with an osmolarity of 460 This website uses cookies to improve your experience while you navigate through the website. Statistical methods for assessing agreement between two methods of clinical measurement. The pivot point on the arm corresponds to the center of radius of the block. Which country first recognized Pakistan in UNO? direct methods of measuring SG (2) Definition. The advantages and disadvantages of a urine test strip Advantages It is convenient to use. J Vet Diagn Invest. Guthrie RM, Lott JA, Kriesel S, Miller IL. Other uncategorized cookies are those that are being analyzed and have not been classified into a category as yet. Home. Yes, refractometers can be used for both OG and FG readings. Are hydrometers reliable? | Exotic Fish Tank Clinical refractometers have a readout that gives serum albumen and urine specific gravity, which can be used to test for urine sample tampering. 2. although others have reported both higher and lower refractometric results compared with biuret results. Urine specific gravity is a laboratory test that shows the concentration of all chemical particles in the urine. i. Refractometer: determines the concentration of the dissolved particles in the specimen by measuring the refractive index. There are numerous advantages to using a refractometer: Very portable - A hand-held refractometer is easily carried. Refractometers can also measure chemical concentrations, validate mixtures and determine the purity of materials. The Effect of Instrument Type on the Measure of Hydration Sep-Oct 1998;24(5):480-2. Because the enthalpy of solution for gases dissolved in waters is usually, of being able to analyze multiple samples in a short amount of time. Specific gravity of urine fluctuates with the concentration of dissolved substances contained in the sample. Hence, before undergoing urinalysis, you have to inform your doctor if you are taking a particular supplement or if you are under a maintenance drug. Refractometer advantages: Definition. Urinometers are used to measure the specific gravity of urine, a measurement of its density. How does a refractometer measure specific gravity? The urinometer, a type of hydrometer, was used for measuring the specific gravity of urine. However, interclass correlations may not be the appropriate statistical technique because the same variable is being correlated. Refractometers also can be used to calculate serum water concentration. 6 Can you measure final gravity with a refractometer? Refraction of light offers advantages for the determination of solute concentrations because the measurement requires no chemical alteration of the specimen. They have become ubiquitous for the measurement of protein and urine solute concentrations because of their rapidity of analysis, ease of use, and relatively low cost. Some solutes, such as acetone, may cause false increases in specific gravity by refractometry, as they increase refraction but are less dense than water. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. Advantages of Reractometer. First, what are the characteristics of each method? This site needs JavaScript to work properly. Validity of the hydrometer and reagent strips was assessed by comparing them with refractometry, the criterion measure for urine specific gravity.711. using a urinometer, harmonic oscillation densitometry(HOD) and indirectly by usina a refractometer or the chemical reagent strip. The specific gravity of water is 1.000 under conditions of standard temperature and pressure. A urine specific gravity test compares the density of urine to the density of water. The specific gravity can be measured by a. Urinometer : less accurate method. Tester 1 and tester 2 were consistent between trials, but tester 3 and tester 4 were not. WebThe main advantages are, only one or two drops of sample urine is enough and temperature correction not required. This is not surprising because determining the urine specific-gravity value using a refractometer is very objective. Reliability of refractometry, hydrometry, and reagent strips was assessed between trials and among testers. Easy to interpret; Cost-effective; The analysis can be done in just a few minutes of collecting urine. Place the cylinder on the lab bench and read the volume of the water using the bottom of the meniscus and the volume makings on the cylinder. Major discrepancies between biuret and refractometric results have been reported for avian samples. Urinalysis consists of three things: physical, chemical, and microscopic. Alfredo Mendiola 1907 Of. 'Specific gravity' is a function of the number, density and weight of the solute particles present in the urine, and is used as a measure of the concentrating power of the kidney. This study sought to validate clinical measures of urine concentration against the criterion standard, urine osmolality. The urinometer, a type of hydrometer, was used for measuring the specific gravity of urine. Another possible source may be variation in the biuret reagent mixture and assay conditions. These cookies ensure basic functionalities and security features of the website, anonymously. Where should I start working out out of shape? Although urine specific gravity is not regarded as the gold standard, current literature suggests a clinical refractometer is a valid, reliable, and practical method for Normally, you are allowed to eat and drink before urinalysis. A small beam of light (red) is shined at the prism surface. Measurement of Urine Specific Gravity - Topend Sports The .gov means its official. Specific gravity continues to be the most common unit for reporting total solids concentration. National Library of Medicine The sensitivity of the hydrometer and reagent strips was calculated as the number that were both disease positive and test positive, divided by the number that were disease positive, times 100.24 The specificity of a test indicates how well a test excludes disease negatives (ie, those without the condition, such as dehydration). The light that is being focused travels through the substance gets absorbed by the. With no water in the tank, and no weights on the scale, the arm is horizontal. Select keywords from the list above (click to select, click again to deselect). The dipstick is placed in the urine to check for any abnormalities. the density of a solution compared with the density of a similar volume of distilled water at a similar temperature. The following instruments were used to assess urine specific gravity. Instant results - Readings are done "on the spot;" no need to wait for lab results. Picture Source: encrypted-tbn0.gstatic.com. Drops of urine are examined under the microscope to check for the following: Your email address will not be published. Specific gravity = Density of urine / Density of water. the contents by NLM or the National Institutes of Health. from air to urine. 'Specific gravity' is a function of the number, density and weight of the solute particles present in the urine, and is used as a measure of the concentrating power of the kidney. While analog handheld refractometers require an external light source for measurement, digital refractometers use light from an internal LED light source. 2019 Nov 11;19(22):4911. doi: 10.3390/s19224911. Indianapolis, IN: National Collegiate Athletic Association; 1998. If the measurements using the 2 devices are comparable, the differences on the plot should be small and centered on zero. Refractometer measurements were significantly lower than hydrometer or reagent-strip measurements (F2,160 = 8.993, P = .0002). We use cookies to give you the best online experience. There are several advantages to using a refractometer instead of a hydrometer, especially in that the refractometer does not suffer from many of the same shortcomings of the hydrometer. Although some researchers have suggested that glucose15 or protein13 may affect urine specific-gravity measurements with reagent strips, others have concluded that reagent-strip measurements are not affected by the presence of glucose13,18 or protein,18 as discussed previously. Popowski et al11 also concluded that measurement of urine specific gravity by refractometry was a valid assessment of hydration status, although it may lag somewhat behind plasma osmolality during progressive acute dehydration. Any abnormalities can be linked to a particular disease or illness. (3) For the determination of specific gravity of canine urine the urinometer is often used. Vet Clin Pathol. The urinometer, a type of hydrometer, was used for measuring the specific gravity of urine. 8600 Rockville Pike Investigators in the previously described validity studies all compared hydrometry or reagent strips with refractometry using interclass Pearson correlation coefficients. Example Sentences: (1) There is no correlation between the relative supersaturation of CaOx and the SG-determination ( urinometer, test stick). This cookie is set by GDPR Cookie Consent plugin. The dotted line represents zero difference between the 2 methods and the 2 solid lines 2 standard deviations of the difference between methods. Swirl the urinometer slightly as it is inserted.make sure the instrument floats freely away from the sides of container. (5, 6). The apparatus shown in Figure 1 will be used. Save my name, email, and website in this browser for the next time I comment. Interobserver reliability of canine urine specific gravity assessed by analog or digital refractometers. What are the advantages of using a refractometer instead of other specific gravity measurement equipment used in clinical microscopy? Describe the principles of the urinometer, refractometer and harmonic oscillation densitometry methods for determine specific gravity. WebThere are numerous advantages to using a refractometer: Very portable - A hand-held refractometer is easily carried. All rights reserved. Several investigators1315 have suggested that reagent strips are an acceptable alternative to refractometry. When the new wrestling rules were first introduced in 1998,4 the NCAA allowed the use of all 3 methods to assess urine specific gravity. What are the advantages of using a refractometer instead of other Urine If you want to brew beer at home or even go pro, youll need a hydrometer; theres no doubt about that. The reagent strips were not reliable between trials for the testers or among testers. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". They have become ubiquitous for the measurement of protein and urine solute concentrations because of their rapidity of analysis, ease of use, and relatively low cost. The purpose of this lab is to separate a mixture and determine the percentages of each of the ingredients. Required fields are marked *. Hunt V. Sport pins down new regulations to help ensure safe competition. Sensitivity and specificity of the hydrometer were 88% and 67%, respectively. Four hydrometers cost more than one refractometer. Easy to interpret Cost-effective The analysis can be done in just a few minutes of collecting urine. 2021 Feb 15;11(2):507. doi: 10.3390/ani11020507. Each tester measured the specific gravity of each urine subsample in the following order: reagent strip, hydrometer, and refractometer. Discuss the correction needed to compensate for high molecular substances as glucose or protein in determining the no need to correct for temp The amplifier is used to amplify the signals and that amplified signals are passed through a feedback network and generates the output. Image 3: The image shows the proper way of collecting a urine sample. Next, pour 25 mL of tap water into the graduated cylinder. Anything the body does not need travels from the kidneys through ureters, bladder, urethra, and out of the body. Refraction of light offers advantages for the determination of solute concentrations because the measurement requires no chemical alteration of the specimen. Clinical refractometers, or TS Meters, are found in many hospitals and clinics. Previous researchers have focused on the validity of hydrometry and reagent strips compared with refractometry, rather than on the reliability of the 3 methods. It would only take a few seconds to notice the changes in color. Some of the variation in reported results may be due to differences in design by refractometer manufacturers. It helps assess whether the treatment the patient currently receives is effective.
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