Defining Dry Contact Alarms and Their Use in the Lab

No, it’s not about contact lenses. Dry contacts are alarms that are “volt free.” They are not connected to circuitry, but rather, they operate as a single on/off switch outside your major circuitry.

Dry Contacts vs Wet Contacts

Why “dry” and “wet” contacts? Why use terms typically related to liquids, rather than voltage? Essentially, mercury. Dry contacts are circuit relays that do not have mercury wetted relays; wet contacts do. And… we’ll stop there as dry contacts and wet contacts are the purview of electrical engineers. 

For lab equipment and facility monitoring purposes, dry contacts are simple alarms that provide a notification when a specific parameter, limit, or functionality is outside of normal operations. They do not provide any data or specifics on why a parameter is being breached or what the "General Alarm" is for but they give you a notice that the device needs to be checked on. This makes them easy to use, but hard to incorporate. Let’s explain…

Dry contacts won’t leave you soaked in up-front costs

Number one benefit of using dry contacts vs wet contacts to monitor your lab equipment: simplicity.

Larger complicated systems are more likely to have a large number of dry contact alarms covering myriad conditions. They deliver simple information (e.g., high pressure or low pressure; open or closed; etc.) from a specific device and is often connected to, and calibrated, with that device’s built-in sensors. Even their costs are simple, too, as they don't provide data but still provide critical insights into when a device is malfunctioning and needs a human to review it. These types of alarms should almost always be cheaper to connect than independent sensors that will give you data on the device's functionality. Usually, it’s a “one and done” kind of cost. 

Dry contacts may be a good fit for certain labs that don’t require in-depth data, and only need occasional temperature readings and similar baseline metrics. They can help let you know when something might be wrong, even if they can’t exactly pinpoint a cause, which can be enough for, say, a backup generator or a gas manifold.

But dry contacts may leave you high and dry

If there’s a common thread to the just described simplicity of using dry contacts it’s most certainly that they’re “standalone”. As dry contact alarms “live” outside your circuitry, they are typically isolated from that circuitry as well, giving you the appropriate alarms regardless of issues with the device's internal circuitry. This means the data they detect is incredibly beneficial for labs. Independent sensors measuring CO2 & temperature in an incubator would not alarm if the incubator loses power. They will only alarm after the temperature/CO2 drops because the power failed. A dry contact alarm will provide immediate notification of power failure and a quicker notification than relying on internal parameter data.

There is no data from dry contacts, but they are a critical tool for helping scientists prevent catastrophes and save samples. Labs looking to be on the leading end of research should be getting as much data as possible, but starting with dry contacts is a great, low-cost way to mitigate risk.

Oftentimes, for one project, multiple pieces of equipment are required, multiple people are involved, and multiple locations within a facility (and sometimes outside it, too) are used. This causes innumerable processes and workflows to move an idea to a marketable product, let alone track data across dry contacts.

Dry contacts can, in these cases, leave you without the connected data streams you need to make informed decisions; they can leave you spending more time in gathering back-end data than you saved in up-front costs; they can also result in inaccurate device data as they’re often reliant on the calibration of a device (and if it’s off, they’re off, too); in short, they can leave you high and dry. (Read about more use cases for dry contacts in our white paper, “What is Your CO2 Incubator Telling You?”)

Having a connected system with active contacts (another name for “wet”) instead of passive ones (another name for “dry”) is critical as it gives you a comprehensive view of your facility, equipment, and workflows. Having wet contacts usually means having connected devices, and you’re thereby connected to the data from a complete system rather than just an individual device. 

For labs investing thousands of hours in manual labor and millions of dollars in funding into any given project, a connected system – monitoring air quality, device uptime, temperature, and humidity changes, and a host of other factors – is the only option.

Dry contacts are up in the air when it comes to compliance

Let us not forget the bane of every lab: regulatory compliance. It’s not that using dry contacts will have you out of compliance: you can absolutely, 100% be in compliance using a system of isolated dry contacts. The challenge is proving it.

Should you be audited or otherwise required to prove you’re in compliance, a system of unconnected devices – each separately reliant on the calibration specs of each individual piece of equipment – will not serve you well. The costs you may have saved up-front will evaporate within a few days of constructing an audit trail.

With a connected system, it’s far easier. And with a connected laboratory monitoring system that is also connected to a larger business operations system, it’s easier than easy because it’s often automatic. And if you lean on a laboratory monitoring services provider like XiltriX, audit trails may be “baked in.”

Every service we provide includes dashboards and other analytics and reporting tools that make it easier for you to show compliance and, more importantly, ensure the security and efficiency of your laboratory equipment and facilities.

To learn more about how to monitor your equipment & dry contact devices, read our eBook Lab Equipment Monitoring: