You can mark a threshold in chart by using the stripline.
To mark a threshold in chart, follow the given steps:
Step 1:
By using the start and end properties in striplines object, you can mark the threshold line in horizontal
axis to the chart as follows,
<!DOCTYPE html>
<html lang="en">
<head>
<title>EJ2 Animation</title>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="description" content="Typescript UI Controls" />
<meta name="author" content="Syncfusion" />
<link href="index.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/ej2-base/styles/material.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/ej2-buttons/styles/material.css" rel="stylesheet" />
<link href="//cdn.syncfusion.com/ej2/ej2-popups/styles/material.css" rel="stylesheet" />
<script src="https://unpkg.com/core-js/client/shim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/core-js/2.4.1/core.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/zone.js/0.6.25/zone.min.js"></script>
<script src="https://unpkg.com/reflect-metadata@0.1.3"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
<script src="systemjs.config.js"></script>
</head>
<body>
<app-container>
<div id='loader'>Loading....</div>
</app-container>
</body>
</html>