Pancake Syrup

Laboratory Viscometer Application Data Sheet

USE

Pancake syrup is used as a topping on pancakes.

Test Equipment:

• Instrument: Viscometer or Rheometer
• Spring Torque Range: LV and RV
• Spindle: SC4-31/13RPY Sample Chamber (LV); SC4-18/13RPY Sample Chamber (RV)
• Accessories: Small Sample Adapter, TC-502P Programmable, Refrigerated Bath
• Speed, rpm: 1, 2, 3, 4 and 5 rpm at 4°C (LV/SC4-31 and RV/SC4-18); 10, 20, 30 and 40 rpm at 25°C (LV/SC4-31); 10, 20, 30, 40 and 50 rpm at 25°C (RV/SC34-18)

The Small Sample Adapter™ may be used with various Brookfield Viscometers or Rheometers. In our example, we used a Brookfield LVDV-III+ and RVDV-III+, with Rheocalc™ v3.1 software for automated instrument control and data acquisition. Our test temperatures of 4°C and 25°C were maintained by connecting the Small Sample Adapter™ water jacket to a TC-502P Programmable Refrigerated Bath. Representative data from the analyses are shown in Figures 1, 2 and 3 below:

Figure 1: Pancake Syrup at 4°C and 25°C; Viscosity vs. Speed, RPM

Figure 2: Pancake Syrup at 4°C and 25°C; Viscosity vsShear Rate, 1/s

Figure 3: Pancake Syrup at 4°C and 25°C; Viscosity vs. Shear Rate, 1/s "(log10 scale)"

The data from our analyses show, at both test temperatures, viscosity decreasing as speed or shear rate is increased. This type of flow behavior is sometimes referred to as "shear- thinning". The Figure 1, 2 and 3 graphs also show that the pancake syrup viscosity is higher at the lower temperature, 4°C (Black and Purple Data), than at 25°C (Red and Blue Data). Temperature may greatly affect the viscosities of many different materials; increasing temperature typically decreases the viscosity of a given substance. The dissimilarity in viscosity ranges between the two sets of data at each test temperature, most readily seen in Figure 3, is attributable to the different shear rates created by the two test spindles. Log-log scales, shown in Figure 3, are used to more evenly space data taken over wide ranges of viscosity, for example. Our tests with an RVDV-III+ with SC4-18 spindle and LVDV-III+ with SC4-31 spindle produced on-scale results at both test temperatures. However, when testing at 4°C we had to use speeds slower than those used at 25°C in order to obtain on-scale results.