Add pipe and implement to dashboard/device component

webapp/frontend/src/app/shared/device-hours.pipe.ts

@@ -0,0 +1,16 @@
+import { Pipe, PipeTransform } from '@angular/core';
+import humanizeDuration from 'humanize-duration';
+
+@Pipe({ name: 'deviceHours' })
+export class DeviceHoursPipe implements PipeTransform {
+    static format(hoursOfRunTime: number, unit: string, humanizeConfig: object): string {
+        if (unit === 'device_hours') {
+          return `${hoursOfRunTime} hours`;
+        }
+        return humanizeDuration(hoursOfRunTime * 60 * 60 * 1000, humanizeConfig);
+    }
+
+  transform(hoursOfRunTime: number, unit = 'humanize', humanizeConfig: any = {}): string {
+        return DeviceHoursPipe.format(hoursOfRunTime, unit, humanizeConfig)
+  }
+}