Acids occur naturally as grapes grow and during the eventual fermentation process. Wines have lower levels of acid when there is a hot growing season or when the grapes come from warmer regions. In the proper proportion, acids are a desirable trait, giving the wine a distinct character. The three predominant acids in wine are tartaric, malic and citric. Tartaric acid is the principal acid in grapes and is a component that promotes a crisp flavor and graceful aging in wine. A moderate amount of a wine’s acid comes from malic acid, which contributes to fruitiness. A small amount of titratable acidity comes from citric acid. Wine also contains trace amounts of other acids; the least desirable acid in wine is acetic acid, which, when present in more than a nominal amount, gives the wine a sour or vinegary aspect.
Total acidity, also called titratable acidity, is the sum of the fixed and volatile acids. In the United States, the total acidity is usually expressed in terms of tartaric acid, even though other acids are also measured. Titratable acidity directly affects the color and flavor of wine and, depending on the style of the wine, is sought in a perfect balance with the sweet and bitter sensations of other components. Too much acidity makes wine tart and sharp; too little makes wines flat and uninteresting. Proper acidity in wine is what makes it refreshing and an ideal accompaniment to food. The proper acid level of wine varies, with sweeter wines generally requiring somewhat higher levels to retain the proper balance.
Application-Specific pH Electrode
The HI84502U-01 is supplied with the HI1048B glass body pH electrode featuring CPS™technology to prevent the clogging of the reference junction. Conventional electrodes may clog quickly in biological samples that have a high solids content such as wine must. By design, the HI1048B pH electrode utilizes a polytetrafluoroethylene (PTFE) sleeve junction which controls a steady, predictable flow of electrolyte solution, keeping the junction open. The hydrophobic properties of PTFE repel wetness and coatings.
Piston Driven Dosing Pump
The heart of the HI84502U-01 is the piston driven burette pump. This type of dosing system uses a motor in which each dose is very precisely controlled and the volume dispensed is accurately determined. The piston driven burette is controlled dynamically so that the volume of titrant being dosed is automatically adjusted based on a voltage response of the previous dose. This type of dosing speeds up the wine titration process by allowing for more titrant to be dosed at the start of the titration and then very small doses as the endpoint is reached.
Automatic Stirrer
The built-in stirrer is automatically maintained at a speed of 600 rpm, regardless of the viscosity of the solution being titrated.
| Specification Name | Detail |
|---|---|
| sku | HI84502U-01 |
| Range | Low Range: 0.1 to 5.0 g/L of tartaric acid High Range: 4.0 to 25.0 g/L of tartaric acid |
| Resolution | 0.1 g/L (ppt) |
| Accuracy (@25ºC/77ºF) | 3% of reading or ±0.1 g/L, whichever is greater |
| Sample Volume | Low Range: 10 mL High Range: 2 mL |
| Methods | acid base titration |
| Principle | endpoint titration: 7.00 pH or 8.20 pH |
| Pump Speed | 10 mL/min |
| Stirring Speed | 600 rpm |
| pH Range | -2.0 to 16.0 pH; -2.00 to 16.00 pH |
| pH Resolution | 0.1 pH / 0.01 pH |
| pH Accuracy (@25ºC/77ºF) | ±0.01 pH |
| pH Calibration | one, two, or three-point calibration, four available buffers (4.01, 7.01, 8.20, 10.01) |
| Temperature Compensation | manual or automatic |
| mV Range | -2000.0 to 2000.0 mV |
| mV Resolution | 0.1 mV |
| mV Accuracy (@25ºC/77ºF) | ±1.0 mV |
| Temperature Range | -20.0 to 120.0°C; -4.0 to 248.0°F; 253.2 to 393.2 K |
| Temperature Resolution | 0.1°C; 0.1°F; 0.1K |
| Temperature Accuracy (@25ºC/77ºF) | ±0.4°C; ±0.8°F; ±0.4 K |
| Logging Data | up to 400 ( 200 titrations, 200 pH/mV readings) |
| Electrode | HI1048B glass body pH electrode with BNC connector and 1 m (3.3’) cable (included) |
| Temperature Probe | HI7662-T stainless steel temperature probe with 1 m (3.3’) cable (included) |
| Environment | 0 to 50°C (32 to 122°F); RH max 95% non-condensing |
| Power Supply | 12 VDC adapter (included) |
| Dimensions | 235 x 200 x 150 mm (9.2 x 7.9 x 5.9”) |
| Weight | 1.9 kg (67.0 oz.) |
| Ordering Information | HI84502 is supplied with HI1048B pH electrode, HI7662-T temperature probe, HI7082 electrode fill solution (30 mL), HI84502-50 (230 mL) titration solution, HI84502-55 pump calibration standard (120 mL), 100 mL beakers (2), dosing pump valve, 2000 ?L automatic pipette with plastic tips (2), 5 mL syringe, 1 mL plastic pipette, tube set (aspiration tube with titrant bottle cap and dispensing tube with tip), stir bar, cleaning solution sachets for wine deposits, cleaning solution sachets for wine stains (2), 12 VDC adapter and instruction manual. |
| Warranty | 2 years |
