Tablets in cleanrooms – just a trend or really useful?

Stainless steel tablet (Image Rights: Systec & Solutions GmbH)

Stainless steel tablet IP65 switch (Image Rights: Systec & Solutions GmbH)

Stainless steel tablet IP65 magnetic USB connector (Image Rights: Systec & Solutions GmbH)

Stainless steel tablet backview (Image Rights: Systec & Solutions GmbH)

Tablets have become a part of everyday life, both at home and in the business world. But does a Tablet make sense in a cleanroom or hygienic environment? In which cases would a permanently installed or mobile HMI system be better? There is no single answer to these questions, because it always depends on the processes and situations involved. In the following, Systec & Solutions GmbH explains the points to consider when deciding for or against a Tablet.

How often do my workers have to use the Tablet, and how do they use it?

Whether or not using a Tablet makes sense primarily depends on how often and how intensively your employees have to work with the Tablet.

The more your workers have to input every day, and the more information has to be displayed at the same time, the less suitable a Tablet is, as it normally only has a roughly 10-inch display. Do not forget that the keyboard of a Tablet always appears on the display and so takes up space. A Tablet could nevertheless be useful with the addition of an external keyboard.

How is the Tablet integrated into the work process of my users?

The mobility of a Tablet is both an advantage and a drawback. It can and has to be carried back and forth between different workstations.

If employees are using a scanner at the same time for example, they will not have a hand free for making entries. Generally speaking, one-hand operation is difficult and means that shelves have to be provided for setting down the Tablet at places where workers have to make entries. Employees can also be distracted if using the Tablet whilst walking.

On the other hand, workers are completely free to move with a Tablet and can take it to where it is required. And so just one device can take the place of multiple permanently installed units. That reduces investment costs.

Which applications/software are to be displayed on the Tablet?

Tablets are not particularly suitable for the visualization of DCS, MES or ERP systems, as the display is not big enough. We recommend using HMI systems with larger displays in such cases. The current trend is towards 24-inch HMI systems. Tablets are a good alternative for paperless documentation or for track & trace quality checks, for example.

And how about the ergonomics for my users?

Housed in a fully encapsulated stainless steel casing, a Tablet is ideally suited to cleanroom applications. This type of casing however also makes it heavier. Carrying the device around and constantly entering data with one hand whilst standing mean that this is not an ergonomic solution over the course of time. We advise providing shelves or table and wall mounts for setting down the Tablet to reduce employee posture problems.

The only way to achieve ideal ergonomic workstations is to use height-adjustable, mobile HMI systems equipped with a flexible keyboard and non-reflecting displays. These can be perfectly adjusted to suit each worker.

How thoroughly can a Tablet be cleaned?

The question of thorough cleaning is a prime concern when choosing a Tablet for cleanroom use. Commercially available Tablets have a plastic casing with numerous recesses and openings for connections, speakers or fans where dirt can ingress into the Tablet. Complete wipe or spray disinfection is not possible. Not to mention the fact that the surface of the casing is not suitable for regular cleaning with corrosive agents and becomes slightly rough.

Another aspect is the amount of time your employees have to spend on cleaning to ensure the Tablet does not present any risks. The less suitable the chosen Tablet is for cleanroom applications, the more time-consuming thorough everyday cleaning becomes. Protection class IP65 means that the Tablet can be used in a cleanroom, but gives no indication of how easy it is to clean. Complete, highly efficient cleaning can only be achieved with Tablets designed to satisfy cleanroom standards.

How are Tablets charged?

When choosing a Tablet, it is tempting to just concentrate on its suitability for cleanroom use. No thought is often given to the power connection or the charging station. This does however tend to be the weakest point in terms of hygiene. Although Tablets with protection class IP65 and above are available on the market, some of the associated charging stations do not conform to any protection class whatsoever. Charging inside a cleanroom is thus not possible or is a potential source of risk. So, when buying it is imperative to find out about the corresponding charging system as well.

In constant use without any means of charging, the battery of a Tablet will not last out a full shift. A Tablet also requires time for charging between shifts. It is therefore important to plan a sufficient number of charging points at your workstations. One battery charge is sufficient if the Tablet is not used much in the course of a shift.

Can I save money by opting for a cleanroom Tablet?

One major advantage of a Tablet is that it is initially a much smaller investment than a permanently installed HMI system. Over the long term, however, it is important to remember that Tablets have shorter product and service life cycles. They are not designed for constant industrial usage. Replacing a Tablet may also mean having to undergo a new qualification process on account of ongoing modifications to the models.

Does a Tablet make sense for my cleanroom?

To sum up, it makes most sense to acquire a Tablet for a cleanroom if users only have to confirm or make entries at various stations now and again. The more entries that have to be made, and the more sustained use is planned, the better it is to have permanently installed or mobile HMI systems with keyboards and larger displays. Before making a decision, we advise you to weigh up the investment costs and operating costs of Tablets as compared to permanently installed or mobile HMI systems.

If you decide to use a Tablet, ergonomic aspects have to be taken into consideration. As Tablets have to be set down to make entries, suitable mounts or shelves have to be provided. Sufficient devices and charging points have to be planned in accordance with the usage time and number of shifts involved. To ensure safe and reliable operation under exacting hygiene conditions, there is no alternative to devices with stainless steel casings developed specially for cleanroom applications. These are designed for use in class D, C and B cleanrooms and permit efficient cleaning.

The following overview lists the advantages and disadvantages of the various options for ease of comparison:

Applications

- Tablet
    - DCS - Not suitable
    - MES - Not always suitable
    - ERP - Not suitable
    - Paperless documentation - Suitable
    - Track & Trace - Suitable

- Mobile HMI system
    - DCS - Suitable
    - MES - Suitable
    - ERP - Suitable
    - Paperless documentation - Suitable
    - Track & Trace - Suitable

- Permanently installed HMI system
   -  DCS - Suitable
   -  MES - Suitable
   -  ERP - Suitable
    - Paperless documentation - Suitable
    - Track & Trace - Suitable

Mobility

- Tablet - Full mobility possible
- Mobile HMI system - Full mobility possible
- Permanently installed HMI system - Not mobile

Investment costs

- Tablet - Low, as lower price and use at various stations possible. No installation costs necessary
- Mobile HMI system - Moderate, as one device can replace different fixed installed devices. No installation costs necessary
- Permanently installed HMI system - High, as each station requires its own HMI system and installation costs are necessary

Operating costs

- Tablet - Moderate, on account of shorter product and service lives
- Mobile HMI system - Low, as long-term use is possible
- Permanently installed HMI system - Low, as long-term use is possible

Ergonomics

- Tablet - Poor to moderate, as dependent on shelves/corresponding table or wall mounts for setting down
- Mobile HMI system - Good, as large display and keyboard can be ergonomically adjusted to the user
- Permanently installed HMI system - Good, as large display and keyboard can usually be ergonomically adjusted to the user

Cleaning

- Tablet - Depends on model. Guaranteed with cleanroom-compatible models. Critical with commercially available models.
- Mobile HMI system - Good, as specially developed for cleanrooms
- Permanently installed HMI system - Good, as specially developed for cleanrooms

Are you planning to use Tablets or HMI systems in your cleanroom?

Systec & Solutions would be pleased to explain the advantages and disadvantages of the various options in relation to your particular requirements. So you can be sure of finding the ideal solution for your users.

Systec & Solutions can supply a stainless steel Tablet casing designed specially for cleanroom requirements. This can accommodate a Microsoft Surface Tablet, for example. The company can also provide further casings for other models on request. The casing is fully enclosed and has a magnetic charging connection and on/off switch conforming to IP65. Simple and efficient cleaning are thus guaranteed.

The well-established WAVE and PILOT HMI systems are available both as a mobile solution under the name TROLLEY and as permanently installed units on a variety of support arms.