Archive for category siemens
Everyone agrees that it’s good practice to keep a record of configurations and setups for any field instrument. I’m constantly recommending it to our customers for their transmitters, controllers, recorders, and other complex configurable devices.
Siemens clamp-on ultrasonic flowmeters even have a system in place to make this process easy. By connecting the meter to a PC through the RS-232 serial port, you can use a terminal program and the SITE command to fetch a data file that holds all the instrument’s configuration data.
The terminal program can also be used — with a set of instructions specific to the flowmeter — for viewing real-time operational data, performing device setup, uploading logger data, or uploading configurations known as SITE setups.
Recently, I was called to visit a plant and look at a misbehaving flowmeter. From previous discussions with the operator, I knew he’d saved SITE setup files for every flowmeter installed in the plant.
I asked if the customer would e-mail me the setup file before my visit, so I could check out how the flowmeter was set up. My request was met with a chuckle and “Well, if you really think it’s worth it…”
Recently, we’ve run into a few radar level applications that had some startup challenges, mostly because the person installing the transmitter didn’t consider how radar wave transmission would affect the level transmitter’s performance.
One trick to any installation is to reduce the number of obstructions encountered by the transmitter. But you have to take into consideration that radar waves don’t transmit in a concentric circle around the transmitter. And this can create a problem of its own.
A process plant’s technician was mystified about how to get a typical gauge pressure transmitter to read in the vacuum range. “All our gauges are 0 to 30 inches mercury, and that’s what we need to transmitter output to be. But the transmitter you sent us just stays around 4mA when we pull a vacuum.”
We walked out to the reactor vessel to look at the installation. The transmitter’s Low side port was open, its high side port was plumbed into a tee along with a conventional bourdon tube pressure gauge reading gauge pressure vacuum.
I could see why he was confused. The mechanical gauge goes from 0 to 30. I asked what range he used to configure the pressure transmitter. His answer, “0 to 30 inches mercury, same as the mechanical gauge.”
So, what was happening?
The easy answer: Yes.
But in a recent webinar on choosing the best level technology for your application, the more specific answer is this: Yes, AS LONG AS you pay attention to the unit specs and a pretty simple rule of thumb.
Recently, a refinery customer came to use with a level application. Our team determined that it would be a perfect fit for radar level gauges, IF they turned on a Siemens radar algorithm called CLEF, that would let the radar measure accurately all the way to the bottom of the tank.
What is CLEF? How does it work? And why does it matter?
Recently, a customer noticed that the Siemens ultrasonic level measurement system he had installed in a storage bin showed a signficant amount of moisture buildup. At extreme temperature changes (like we’ve seen a lot latele here in the Midwest), there’d be moisture buildup on the Echomax ultrasonic transducer, sometimes so severely, they’d have problems from signal loss.
How could they fix it? One quick trip to the local big-box or auto supply store provided a Siemens-supported solution.
Before I talk about the value of a universal 4-20mA analog output on a level controller, let me explain why anyone would care. It’s all about ground loops.
Since the early days of electronic instrumentation, way back when, even before cell phones or PCs, instrument people struggled with ground loops that create an offset error, drive the signal off scale, or burn up an analog circuit.