Array is not rendered through jade in node js

viewDevice.jade:

tbody
    for device in devices
        tr.odd.gradeX
            td #{device.device_name}

index.js:

router.get('/viewDevice', function(req, res, next) {
    console.log("In view Device");
        dat = '';
            request.get('http://localhost:8081/api/device','',function(err,res,body){
                if(res.statusCode !== 200 ) {
                    console.log("error");
                    }
                else{
                    dataStr = body.toString();
                    dat = JSON.parse(dataStr);
                    console.log(data);
                    }
                });

    res.render('viewDevice', {devices:data});
});

Sample response/array:

[ { id: '7',
device_name: 'BP Monitor 1',
device_type: 'BP monitor',
device_description: 'Used to measure BP for person 1',
device_status: null },
{ id: '9',
device_name: 'Glucometer 1',
device_type: 'Gluco Monitor',
device_description: 'Glucometer for person 1',
device_status: null } ]

Please help. The array is not getting rendered in jade. No error can be found.