Ohaus, pH Meters & Thermal Cameras: An Admin Buyer’s Honest Buying FAQ

When our lab manager came to me in 2024 asking for a new pH meter, I figured this would be like buying a printer – pick a known brand, compare two prices, done. Eight vendors and three spec sheets later, I realized I was wrong. But this time I decided to learn from the challenges we've seen, not from our purchasing team's mistakes.

I've managed lab and office supply orders for a 400-person research company across three sites since 2020. In that time, I've handled roughly 60 to 80 purchase orders per year – for things like calibrated scales and scientific instruments – and I've had to make some pretty specific decisions. So this FAQ is for anyone in a similar position – someone who gets asked for an Ohaus product or a thermal camera and secretly wonders if they're about to order the wrong thing.

What do I need to know about Ohaus? Is it just a budget Mettler?

That's what I assumed back in 2020. The first time I saw the Ohaus name, it was on a quote that was about 25% lower than a comparable Mettler Toledo. My initial reaction was that it was the "good enough" option, or perhaps a budget-friendly substitute. About six months into using our first Ohaus Explorer analytical balance, I realized I was wrong.

Ohaus has been making balances since 1907. They're a serious precision weighing brand that serves education, industrial, and research labs. They're not trying to be the premium option; their niche is making reliable, user-friendly instruments at a price that makes sense for laboratories that don't have an unlimited budget. They are also owned by the same parent company that owns Mettler Toledo (in case anyone in procurement finds that interesting).

One caveat: their premium analytical balances like the Explorer or Analytical Plus are on a different level than their portable models. If your lab requires very advanced software integrations with 21 CFR Part 11, you should consider all options, including Mettler or Sartorius.

Are ohaus Aquasearcher pH meters worth it?

If you ask me for a specific recommendation from my purchasing history, I'd say yes, but with a few conditions.

The Aquasearcher series (AB23PH, AB33PH, etc.) is Ohaus’s line of pH meters designed for both routine and more advanced measurements. We purchased the AB23PH for two of our general-purpose labs in March 2024, after I had been going back and forth for about two weeks. The upside was a reliable pH meter at an intermediate price point. The risk was that they might not be as robust as other models. I kept asking myself: is saving $300 per unit worth potentially dealing with service issues later?

So far, they've actually been quite solid. It has automatic buffer recognition, a clear LCD, and a surprisingly stable electrode. For laboratories that do 15-20 pH readings per day, I think it's very suitable.

Here's what I wish I knew before ordering: the electrode is not indestructible. The first one in our lab was damaged after a summer intern left it sitting in distilled water for two weeks. That's a user training issue, not an equipment issue.

What about laboratory pH meters? Are there specific features to look for?

After reading the spec sheets, I found that their features are fairly comparable across brands. For a pH meter, I would focus on:

• Number of calibration points: For general purposes, look for something that supports at least 3-point calibration. Most models in the mid-range do this.
• Electrode type: Some come sealed and are easier to use, while others have refillable electrodes that cost less to use over time, but require more care.
• IP rating: In our lab, we purchased the IP54-rated model because of the risk of splashes. This is not just about dust; it’s about protecting the meter from accidental liquid damage.

What I personally find confusing is why some premium pH meters include a printed paper calibration certificate, while others require you to download it. If you're being audited (ISO 9001 or similar), you'll want to make sure the meter you're buying has that certificate readily available. I can confirm that the Aquasearcher models include a certificate of conformity.

What exactly is an optical spectrum analyzer?

Honest answer: I began researching these devices because our engineering team requested one for a project, and I'm an admin buyer, not an engineer. So I asked around and read up, and here's what I've found useful.

An optical spectrum analyzer (OSA) is a precision instrument used to measure the power of light across a portion of the electromagnetic spectrum. In many industrial and research contexts, it measures the optical power versus wavelength to assess the properties of lasers, optical fibers, or other light sources. It's used by engineers in fields such as telecommunications to check the wavelength of a laser source, or ensure that an optical signal is within a specified channel plan.

I used to think they were a single, standard type of device. Wrong. There are different architectures: grating-based, interferometric, etc. The price can range from a few thousand dollars for a basic device, to tens of thousands for high-resolution research-grade equipment. If you're in procurement and an engineer comes to you with a request for one, you need to ask them for three specs: wavelength range, resolution bandwidth, and power sensitivity.

Otherwise, you'll end up with a general device that is either expensive or unsuitable, and that doesn't help anyone.

And what should I know about the Iperl water meter?

I had to dig into this one too, mainly because I wasn't familiar with Iperl. From what I've gathered, Iperl makes ultrasonic water meters, which are a modern alternative to traditional mechanical water meters used for measuring water flow in buildings or industrial applications.

The reason they're becoming popular in facility management is that they have no moving parts. Because of this, they can potentially provide more consistent readings over time and require less maintenance than mechanical meters. They also often support remote reading via data interfaces, which is a huge plus for facilities.

For lab environments, they aren't on my radar. But for a building’s main water line or irrigation monitoring, I'd say it's worth investigating. My main advice, based on a past issue where our procurement team almost picked the wrong sensor, is to check what communication protocol the building uses (e.g., pulse output, Modbus, LoRaWAN, etc.). Getting a meter that doesn't connect to your existing system is a mistake.

Can thermal cameras see through glass? FLIR specifically

Short answer: no.

When I first started working with our maintenance team, I was pretty sure thermal cameras could see everything, and I assumed you could point them through a window to find heat leaks. My colleague laughed and told me to try it. In fact, if you point a thermal camera at a window, you will see the reflection of the room (or your own body heat) rather than the temperature of objects on the other side.

Why is that? Glass blocks infrared radiation. A thermal camera like a FLIR model detects long-wave infrared (LWIR), and glass reflects that band. So instead of seeing through the window, you see a mirrored thermal image. A few tips from our experience:

• Use a special IR-transmissive window or viewport material if you need to measure through glass.
• Don't point a thermal camera at a car window or a glass office partition to see if someone is inside.
• If you're doing a building energy audit, you should inspect the exterior from the inside during winter when it's cold outside, and vice versa in summer. Just be mindful that reflections can confuse you.

I'm not 100% sure, but FLIR's FAQ likely states the same thing. It's a physical limitation, not a manufacturer limitation. If an engineer tells you they can see through glass with a thermal camera, they are probably mistaken.

Budgeting: are Ohaus pH meters and balances a good value?

In my experience, the value depends on what you're comparing them to. Let me give you a rough idea of the price range we encountered:

• Aquasearcher AB23PH benchtop pH meter: Usually between $500-$900 depending on the package and electrode, based on quotes from authorized distributors in March 2025.
• General purpose Ohaus balances (e.g., Pioneer or Adventurer): $1,000 to $2,500 for most lab models.

So if someone asks me about a $1,800 Ohaus analytical balance vs. a $2,800 Mettler Toledo model, I would say: it's worth comparing the readability, repeatability, and stability. If your application is general weighing and you don't need expensive software traceability, choosing Ohaus can free up budget for other things, like electrodes or additional calibration weights.

That said, I always advise colleagues to check whether the model you're getting has the built-in calibration feature. Some Ohaus models include an internal calibration weight (often indicated by "i" in the model name), which is worth the extra money from a maintenance perspective, especially if you don't want to deal with external weights.

Is there anything else a procurement person should consider when buying a pH meter?

One consideration I don't see mentioned often in product descriptions, but that we learned the hard way: ongoing costs and lead times for electrodes. For our old pH meter from another brand, the electrode cost $120, lasted around 8 months, and sometimes took 3 weeks to deliver.

So I want to get the electrode availability confirmed before purchasing any meter. Not all brands are transparent about that information.

Here are a few final and practical pieces of advice:

• Do not buy a pH meter without checking the price of a replacement electrode.
• Confirm whether the meter allows for electrode calibration. Some electrodes have a built-in temperature sensor. If you buy the wrong one, the meter might read temperature inaccurately.
• For laboratories subject to audits, request a certificate of calibration. Don't assume it's included.
• And if you're purchasing thermal cameras, I recommend buying an extra battery. They drain fast, particularly in cold environments.

There isn't one perfect brand that suits all scenarios. What matters is that the person buying the equipment has a clear understanding that "thermal cameras blocked by glass" and "pH electrode replacement costs" are just as important as the actual purchase price. Understanding these trade-offs can save you a significant amount of stress and financial loss later on.