Model Name Plato: Valid for SRD

# 1. What it does do?

Determines concentration of dissolved solids in a brewery wort from line density and temperature.

# 2. Application

Breweries / Beverage

# 3. Maths

Below finds the mathematical formula for Plato's degree calculation.

To obtain the correct measurements for Plato's degree, the SRD and SMET work together as a powerful tool for measuring density, which is an extremely significant variable. The user would need to input:

3.1. Input Water density at T2 (20°C – Plato). Needed for Specific Gravity @20°C calculation. Compensated density with Temperature T1 is calculated with the values measured with SMET.

3.2. Measure process line density and line temperatures. Values are taken from SMET-SRD.

3.3. Convert the line density of process fluid to temperature compensated for density value at T1 (20°C –Plato) – By using a dataset table from a known product.

# 4. How to load models into the SMET?

The calculation tab allows configuring the SMET to run mathematical models for Viscosity, Density, and Concentration.

Figure 1. Calculation tab for Brix degree model

The following steps are to load the models into SMET:

- In the Dropdown list “Select Measurement to Apply Model” select. That will modify the “Select Model from List” dropdown menu values. Select Measurement application (Concentration)
- In “Select Model from the list” select the model you would like to use for the specific parameter. When you select the model, you will get more information about the specific equation used and the coefficients you will need to apply that model. Select “Plato”
- “Load Dataset” button,
**this operation is crucial to get the correct measurement for Plato degree so as density and temperature to be the measurement from the process must be within this table**. Dataset table must cover at least the following instances:

- Five reference temperatures (at least)
- The density for each of four product types at the five reference temperatures from Process (20 reference points in all, at least)
- The base temperature(20°C), must be one of the five reference temperatures.
- Guarantee inline density value is between the density values from the table otherwise output from SMET will be NaN.

# 5. Matrix Referral

Figure 2. Sample Dataset for Brix readings.

5.1. Dataset for 20 dataset point, first column is for temperature. The rest of the columns should be each for a product "P", and the densities of that product at the different temperatures.

5.2. Import: Select dataset from an .csv sheet

Figure 3. Selecting dataset

5.3. Export: Export current table to .csv

5.4. "Tk1, Tk2" button to create the coefficients that will be used on the model.

5.5. Calculated Tk coefficients by internal model.

5.6. "Load Tks & Close" button to load these coefficients into the model

# 6. Uploading the Mathematical Model

Click “Upload Model” to load the model settings into SMET. The button should turn GREEN for a couple of seconds if the action was successful or turn RED if the operation was Rheonics Control Panel Software unsuccessful. This action will refresh the values for the Uncompensated and Compensated indicators. Here you can verify if the model is calculating the expected values. If not, you can correct and repeat the process.

Figure 4. Plato model loaded into the SMET.

6.1. Click “Load Configuration” to update the display and channel configurations in SMET.

- LCD Display

Select the line to display the parameter:

Figure 5. Selecting read line for LCD display

Changes can be verified on the “Communication” Tab

- Analog outputs

Select analog channel to send data, this can be verified in “Service” Tab

Figure 6. Selecting analog output channel

- Modbus TCP/IP register

Measurement can always be accessed at the register address that is displayed.

- “Calculation History” button allows you to open a file where the last uploaded models and coefficients for these models are stored. This is for user reference.