node-red sample B

var socket;
var temperatureData, humidityData;
var temperatureOptions, humidityOptions;
var temperatureChart, humidityChart;

// Google Gauge
google.load("visualization", "1", {packages:["gauge"]});
google.setOnLoadCallback(drawChart);
function drawChart() {
    // Data for temperature chart
    temperatureData = google.visualization.arrayToDataTable([
            ['Label', 'Value'],
            ['Temperature', 0],
            ['Object Temperature', 0]
            ]);

    // Data for humidity chart
    humidityData = google.visualization.arrayToDataTable([
            ['Label', 'Value'],
            ['Humidity', 0]
            ]);

    // Option for temperature chart
    // If you want to set other options, please refer to https://developers.google.com/chart/interactive/docs/gallery/gauge
    temperatureOptions = {
        width: 400, height: 120,
        min: 0, max: 60,
        redFrom: 50, redTo: 60,
        yellowFrom:40, yellowTo: 50,
        minorTicks: 5
    };

    // Option for humidity chart
    humidityOptions = {
        width: 400, height: 120,
        min: 0, max: 100,
        redFrom: 90, redTo: 100,
        yellowFrom:75, yellowTo: 90,
        minorTicks: 5
    };

    temperatureChart = new google.visualization.Gauge(document.getElementById('temperatureChart'));
    humidityChart = new google.visualization.Gauge(document.getElementById('humidityChart'));

    temperatureChart.draw(temperatureData, temperatureOptions);
    humidityChart.draw(humidityData, humidityOptions);
};

function connect(wsUrl) {
    socket = new WebSocket(wsUrl);
    socket.onmessage = function(e) {
        var sensorData = JSON.parse(e.data);

        // Update temperature data
        temperatureData.setValue(0, 1, sensorData.temp);
        temperatureData.setValue(1, 1, sensorData.objectTemp);

        // Update humidity data
        humidityData.setValue(0, 1, sensorData.humidity);

        temperatureChart.draw(temperatureData, temperatureOptions);
        humidityChart.draw(humidityData, humidityOptions);
    };
};

function disconnect() {
    socket.close();
};