Appropriate an option of measurement equipment is crucial for the development and manufacturing of food products in a consistent, efficient and timely manner. Item such as refractometers, pH meters, thermometers and scales are just a few pieces of tools that little businesses might take into consideration when make initial equipment purchases. The purpose of this fact sheet is come provide basic information about the function and capabilities of measurement devices for food product breakthrough and manufacturing.


Refractometers can be offered to measure up the concentration that solutes in solution, such as sugar, salt and also even automotive fluids. However, each refractometer is specifically designed to measure up the concentration of a specific item. In other words, refractometers deserve to be product specific. Additionally, some varieties of refractometers only operate in ~ a certain range. Therefore, the is extremely vital when to buy a refractometer to choose the correct form so dimensions will be accurate and also meaningful.

Temperature have the right to influence the accuracy the a refractometer’s readings of the sample. The is often recommended samples be allowed to pertained to room temperature prior to measurements are taken. Unfortunately, room temperature may vary by season (winter vs. Summer) and location (production floor vs. Lab). Therefore, to buy a refractometer that has actually automatic temperature compensation (ATC) is a great way to minimize temperature-induced variations in measurements.

There room two formats of refractometers frequently used in food processing:

Portable Handheld Refractometers

These devices are much less expensive and also can be easily lugged into the manufacturing environment to take it measurements. However, they will usually only cover a limited range the brix values; therefore, it might be essential to acquisition several portable models come ensure all of the wanted solute concentrations deserve to be measured. For example, measuring the brix in fresh apple juice could require a refractometer v an operating variety of 0 to 18 degrees brix; however, measure the brix in to apologize jelly could require a refractometer v an operating variety of 40 come 70 degrees brix.

Bench optimal Refractometers

These devices are much more expensive; however, a solitary unit can commonly be offered to measure brix across the entire selection of feasible values. Digital bench height models additionally are available that instantly measure and display brix readings. These systems can aid reduce the variability in between measurements take away by various operators due to the fact that the measurements are read electronically fairly than construed by a particular operator.

pH Meters

Acidity or alkalinity of foods is measured using a pH meter. Foods items that have a short pH are acidic and also often taste sour. Foodstuffs with a high pH room alkaline and also often taste bitter. Since pH have the right to be a limiting factor in microorganism growth and survival, it i do not care extremely necessary to monitor the pH of countless foods come ensure the growth of disease-causing microbe is prevented. To properly measure pH, certain factors needed to it is in considered:

Resolution and Accuracy

Federal agencies typically require that pH readings be report to the nearest tenth (0.1) that a unit. While countless pH meter are qualified of this resolution, the accuracy selection of the meter likewise must it is in considered. Plenty of less high value pH meter may have actually an accuracy of to add or minus 0.2 units. Therefore, an inexpensive meter reading a pH that 4.5 actually suggests the pH value drops within the range of 4.3 come 4.7. This would be exceptionally problematic due to the fact that there is the possibility that the legit pH limit of 4.6 (established for plenty of products) had actually been exceeded. That is therefore advisable come invest in a pH meter that offers a resolution and accuracy the at the very least 0.1 pH units.

Detachable or All-in-One Probe

Meters come v probes that room either detachable or space an integrated part of the meter itself. If both species of meters role equally well, those through detachable probes are much more expensive. However, pH probes only have actually a expectancy of one to three years, escape upon problems of use. Therefore, pH meters with detachable probes allow users to replace just the probe when necessary, while all-in-one units must be replaced entirely.

Electrode Type

The electrode is the pH sensing unit that the meter, and in certain species of probes, it is

located in ~ the tip of the probe in a glass bulb. This electrodes might be either sealed or refillable. Sealed probes require much less maintenance and are less complicated to use, while refillable probes might last longer due to the fact that their design allows them to it is in cleaned and “rejuvenated.” However, no all probes are created of glass. Solid-state probes additionally are available, yet they might be more expensive. View pH meter for an ext information.

Auto Calibration and also Temperature Compensation

Auto calibration and temperature compensation functions are typical in plenty of pH meters. These functions make it easier to calibrate the meter and read the pH the samples. Users of meter without these attributes will need to adjust the meters manually during calibration, sample reading or both to ensure precise measurements.

For additional information top top pH meters, see truth Sheet FAPC-117, “Choosing and using a pH meter for food products” through Dr. Wilhelm McGlynn.


Thermometers play an extremely important duty during the manufacturing and also storage of foods by ensuring that appropriate temperatures space maintained. Over there are several different types of thermometers that might be used, each with benefits and disadvantages.

Liquid-filled Thermometer

It is illegal to usage this form of thermometer in restaurants or food organization establishments as the glass and also inner liquids (mercury or alcohol) deserve to pose physics or chemical hazards.

Bimetal Thermometer – oven Safe

Response speed: 1-2 minutes

Placement: 2 come 2-1/2 inches deep in thickest component of food

Suggested Use: roasts, casseroles, soups


deserve to be inserted in food while cooking Not appropriate for thin foods Heat conduction of steel stem can reason false high analysis

Bimetal Thermometer – immediate Read

Response speed: 15-20 secs

Placement: 2 come 2-1/2 inches deep in thickest part of food

Suggested Use: roasts, casseroles, soups


check internal temperature of food at finish of cooking time deserve to be calibrated Cannot measure thin foods unless put sideways temperature averaged along 2-3 customs of probe

Thermistor Thermometer

Response speed: 10 seconds

Placement: ½ customs deep

Suggested Use: hamburger patty, pork chops


Digital measures temperature in thin foods Cannot be offered in oven while food preparation

Thermocouple Thermometer

Response speed: 5 secs

Placement: ¼ inch deep or deeper

Suggested use: hamburger patty, pork chops


Digital quickly measures thinnest foods items Can be calibrated

Disposable Thermometers

The accuracy and resolution the the different thermometers can vary based upon make and model. Both the digital thermistor and also thermocouple thermometers deserve to have accuracies of add to or minus 1 degree C/F and resolutions the 0.1 C/F, if bimetal dial thermometers can have accuracies of add to or minus 1 percent of the dial variety at any suggest on the dial.


Scales for sure ingredients space weighed consistently and also the perfect product weighs a

specified amount. This is very important since inaccurately measured ingredients deserve to be a resource of sports in product appearance, flavor and texture. Additionally, finished product that is under-filled may be reputed misbranded and subject to recall.

There room three styles of scales the are generally available: electronic top-loading, mechanical and also electronic analytical.

Electronic Top-loading Scales

These scale are uncovered throughout food processing environments, in labs or ~ above the production floor. Electronic top-loading scales uncovered in labs may be provided to measure up ingredients that weigh several tens or numerous grams. This scales room compact and also can be positioned on counter tops for this reason that little sacks or containers may be quickly placed on them. The resolution will vary relying on the scales’ maximum capacities. A scale with a maximum capacity of 500 grams may have a resolution the 0.01 grams when a range with a maximum volume of 4,000 grams may have actually a resolution of 0.1 grams.

Electronic top-loading scales found on the production floor may be supplied to measure ingredients the weigh several tens or hundreds of pounds or kilograms. They space typically large and positioned near or on the floor to permit sacks and also barrels come be easily placed ~ above them. These systems are built of aluminum or stainless stole for durability. Additionally, they might be water-proofed to run in high moisture areas and to stand up to wet cleaning procedures. As discussed above, the resolution of these scales will certainly vary depending on maximum capacity. A scale with a maximum capacity of 25 pounds may have actually a resolution of 0.005 pounds (0.002 kilograms) while a range with a maximum capacity of 500 pounds may have a resolution the 0.1 pounds (0.05 kilograms).

Mechanical Scales

Mechanical scales additionally are known as single, double or triple beam balances. They room

sometimes offered in laboratories and pharmacies. While this scales room usually less expensive than digital models, castle require much more skill and also time come calibrate and read. These attributes often make mechanical scales unsuitable for use in a food manufacturing facility.

Electronic analytical Scales

These scale are the same to digital scales; however, castle are used for measure up extremely small weights and may have actually resolutions in the thousandths (0.001). This scales are often used in laboratories that do chemical analyses; however, because of their fairly low best capacity, they would more than likely not be used for routine measurements in a common food production facility.

Additional determinants to Consider

For every of the previous piece of measurement tools discussed, there room several added factors that must be considered.

Ease of Use

The cost of equipment, new or used, can frequently be expensive for entrepreneurs and small businesses, and purchasing the the very least expensive unit easily accessible is often the best, and only, option. However, future growth and also needs should be anticipated. What is the operating selection of the equipment, and also will you exceed it within a year? can the devices withstand the enhanced wear and also tear of longer hrs and an ext shifts of production? What will certainly it cost to maintain? To stop repeated to buy or consistent maintenance problems, these questions must be considered.


The reliability and accuracy of equipment can only be preserved through continual maintenance and also calibration. This becomes imperative when handling equipment such as thermometers and pH meters that might be used to screen some aspect of food safety.

Depending ~ above the food product and process, regulatory guidelines might govern the frequency of tool calibration and maintenance. See truth Sheet FAPC-117 “Choosing and using a pH meter for food products” for extr information about calibration that pH meters. Also, view FSIS guidelines for information regarding the calibration of thermometers.


As stated previously, some varieties of tools can it is in cleaned by washing the whole unit v water and also detergent; however, equipment that cannot gain wet might need to be disassembled or might require special procedures for sufficient cleaning. Devices meant to be provided on the production floor might be created from more durable materials than the equivalent laboratory model which normally adds far-reaching cost.


Proper equipment selection is crucial part of establishing a effective food advance and production business. Factors such as tools capacity, ease of use, maintenance and also durability need to be considered prior to purchases room made. Additionally, any needs as result of future growth also should be considered to ensure optimal equipment selection. You re welcome feel totally free to call the Food & farming Products center for added information to help in devices selection.


U.S. Food and Drug Administration, FDA customer Magazine September–October 1998. All about Cooking Thermometers. Http://

Food & agricultural Research and an innovation Center. Oklahoma State University. Fact Sheet FAPC-117. Choosing and also using a pH meter for food products.

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Wilhelm McGlynn.