The 7-Point Ashcroft Instrument Checklist I Use Before Ordering Pressure Gauges and Thermometers

I've been a maintenance engineer for eight years, and I've personally made—and documented—11 significant mistakes when ordering pressure and temperature instruments. Total wasted budget: roughly $17,000. I'm not proud of that number, but I now maintain our team's checklist so nobody repeats my errors.

This checklist is for anyone who buys pressure gauges, digital pressure gauges, or dial thermometers. If you're choosing an Ashcroft 1009 pressure gauge, an Ashcroft digital pressure gauge, or the Ashcroft dial thermometer 50EI60E, these seven steps will keep you out of the sort of trouble I walked into. It assumes you already know basic process data. If you don't, stop before you order anything.

The 7-Step Checklist

Step 1: Confirm the real measurement need

This step looks too simple, which is why people skip it. Are you solving a pressure problem, a temperature problem, a mass problem, or a leak problem? I've had a pressure problem turn out to be a temperature problem. The gauge was bouncing because steam was condensing, not because the pressure was unstable. A dial thermometer—like the Ashcroft 50EI60E—was a better first instrument than another pressure gauge.

People ask me: What is a FLIR thermal camera? Short answer: it's an infrared thermal imaging camera made by FLIR. It shows heat patterns as an image. It's great for finding hot spots on electrical panels or tracing steam leaks. It is not a pressure sensor and it won't tell you line pressure. That's not a flaw; it's a boundary. Different jobs require different tools.

Same with mass. If you need to know how much material you're putting into a tank, a precision balance is the right tool. A pressure reading can be used to infer level in a tank, but it's not the same as a weight measurement. I've watched inventory arguments happen because people treated tank pressure like a precision balance measurement. It isn't.

Step 2: Check wetted materials and process compatibility

Your process fluid doesn't care what the model number says. The Ashcroft 1009 pressure gauge is a workhorse for general service, but general service is not universal service. On the standard model, the wetted parts are copper alloy. That works for air, oil, water, and many hydraulic fluids. It does not work for every chemical. I once put one in a line with a trace amount of chlorine and watched the pointer get jumpy within a week. The gauge cost wasn't huge, but the production delay was.

Before you order, check the compatibility table for the wetted parts and the case. Ask about the enclosure rating too. If the gauge will sit in a washdown area, a standard tin case might not last a season. This is the step where one extra phone call saves a reorder.

Step 3: Set the range with real headroom

Don't order a gauge where the normal operating pressure sits at the top of the scale. I ordered a 0-100 psi gauge for a system running at 90 psi. The needle sat high, the accuracy was worse, and the operator didn't trust the reading. A lot of pressure gauges have accuracy stated as a percentage of full scale. At the high end, that math works against you.

If normal pressure is 90 psi, a 0-160 psi gauge often gives a better reading because the needle sits in the middle third of the range. The exact choice depends on the manufacturer's recommendations. For an Ashcroft digital pressure gauge, range selection still matters. The digital display doesn't fix a poor range choice. What digital does give you in some models is min/max capture, which is valuable if you're chasing pressure spikes.

Step 4: Confirm connection size, thread type, and orientation

This is where I've lost the most money. I ordered a 1/2 inch NPT gauge for a system with 1/4 inch NPT ports. The quote looked fine. The installation didn't. We spent $890 on adapters, fittings, and labor before it worked. Looking back, I should have verified the connection before I approved the purchase order. At the time, I assumed the phrase standard process connection meant our plant's standard. It didn't.

Orientation is the ignored sibling. A dial thermometer can have its stem in the right place and its dial facing the wrong way. The Ashcroft dial thermometer 50EI60E is a workhorse, but the stem angle and dial position have to work for the person reading it. I ordered one and couldn't read it from the platform because the dial was angled away. That was a $450 mistake plus a two-week delay. Even after I placed the reorder, I kept second-guessing. What if the new angle still didn't line up? I didn't relax until we mounted it on the tank and I read the temperature from where I needed to stand.

Step 5: Think about vibration, freezing, and washdown

Vibration kills dry gauges. The pointer shakes, the movement wears, and you get a reading that changes with the pump speed. If the gauge is near rotating equipment, specify a liquid-filled case. If the site gets below freezing, ask the manufacturer about a low-temperature fill fluid. If the location gets washed down, check the IP rating before you install it.

I had a plant where every gauge looked sealed but none survived the high-pressure washdown. We replaced three in two months. The fourth time, we bought the correct IP-rated version and it's still working. Same brand, same pressure range, different enclosure. The environment question matters more than the brand.

Step 6: Plan for calibration and documentation

If the gauge is going into a quality, safety, or regulated system, calibration paperwork is not optional. In Q1 2024, I sent three gauges out for calibration and two came back with no certificate. That created a long argument with our quality engineer. I still kick myself for not putting calibration certificate with NIST-traceable data into the purchase order. If I'd added one line, we'd have avoided the entire debate.

According to ASME B40.100, pressure gauge accuracy is defined under specific test conditions. That means if you don't know the test method, you don't really know the accuracy. Ask for the test method. For a digital pressure gauge, ask about the reference sensor and the calibration interval. Don't assume digital automatically means accurate forever. It doesn't.

Step 7: Price the installation, not just the instrument

The cheapest unit price is not always the cheapest installation. I once chose a supplier based on gauge price alone, then spent $320 on adapters, a manifold, and a mounting bracket. The quote didn't include the bracket, the fittings, or the extra weekend labor. Now I add 15% to any instrument quote for the things I forgot.

Check internal inventory before ordering. I approved an expedited order one time and immediately thought: did I check the other plant's shelf? Turns out they had the exact model in storage. The rush fee was gone, and so was my pride. Bottom line: lead time and total installed cost matter as much as the price on the gauge.

Common Mistakes I Still See (and Have Made)

The frustrating part? Most of my mistakes were kinda dumb in hindsight.

• Buying a digital pressure gauge when an analog gauge is enough. I'm a fan of Ashcroft's digital line, but if the operator just needs a local reading and no data logging, a digital display is another battery to maintain. Don't over-spec.
• Ignoring the dial thermometer orientation. I listed it as step 4, but I'll say it again. A thermometer with a readable dial is worth ten times a more expensive model with a dial facing the wall.
• Forgetting that a precision balance and a pressure gauge are not interchangeable. If the question is how much mass is in this vessel, the answer is not a pressure gauge. It's a precision balance or a level instrument. Know the boundary.
• Ordering a gauge before confirming the wetted materials. The Ashcroft 1009 pressure gauge is great for general fluid service. General does not mean all. Check the compatibility table, not just the picture.

What This Checklist Doesn't Cover

Quick answer to a common search: What is a FLIR thermal camera? It's a thermal imager made by FLIR. It creates an image based on infrared radiation. That image shows temperature differences, which is useful for finding hot spots, missing insulation, or overloaded circuits. It doesn't measure pressure, and it shouldn't be used as a replacement for a contact thermometer in a calibration loop.

A precision balance is another specialty. If you need mass measurement, use a precision balance with its own calibration program. When a vendor says we can handle every type of measurement with one device, I get nervous. I'd rather work with a specialist who knows the boundary and says this isn't our strength, here's who does it better. That honesty is worth more than a product catalog that claims to be everything.

My checklist won't tell you which thermal camera to buy or how to calibrate a balance. It's for pressure and temperature instruments. That's the point. If you need those other tools, go ask someone who does them well.