Frequently Asked Questions
Q1: What is the 330851-04-000-023-10-01-05 mainly used for?
A: In most cases, people use the 330851-04-000-023-10-01-05 on steam turbine monitoring systems, especially on larger turbine generator units. It’s part of the Bently Nevada 3300 XL 25 mm Probe family and is commonly selected for differential expansion (DE) measurement. During turbine operation, the rotor and casing expand differently because of heat, so this kind of 25mm proximity sensor helps track that axial movement before it becomes a problem. The wider 500 mil measuring range is one reason it gets used a lot on heavy rotating equipment.
Q2: What do “-04” and “-000” for the 330851-04-000-023-10-01-05 actually refer to?
A: The “-04” section is related to the probe body style. This version comes with a smooth case design and a side-exit cable, which is usually easier to install where spacing around the housing is limited. You’ll see this kind of setup quite often on older turbine assemblies too. As for “-000”, there’s really not much mystery there — it simply means no unthreaded length is included on the probe.
Q3: Is the 330851-04-000-023-10-01-05 okay for high temperature areas?
A: Yes, that’s actually one of the reasons many plants still use it. The probe tip uses PPS material and the outer housing is AISI 304 stainless steel, so normal turbine heat is generally not an issue. Temperature range goes from around -35 °C up to +200 °C. On some sites there’s also oil vapor, vibration, or chemical exposure near the machine, so the -05 armored cable option helps protect the sensor cable a bit better over time. Not every installation needs that option, but in power plant instrumentation it’s pretty common.
Q4: What kind of signal output does the 330851-04-000-023-10-01-05 have?
A: When paired with a matching 3300 XL Proximitor® Sensor, the output sensitivity is about 0.787 V/mm, or 20 mV/mil. Total linear range is 12.7 mm, which equals 500 mils. The probe starts measuring from roughly 0.63 mm away from the target surface. For non-contact displacement monitoring and shaft position monitoring, that range is usually enough for large steam turbine applications.
Q5: Does the 330851-04-000-023-10-01-05have hazardous area approvals?
A: It does. The -01 option means the sensor comes with multiple approvals, including ATEX, IECEx, and CSA certifications. So if the equipment is installed in hazardous industrial environments, normally there’s no issue meeting common site requirements for intrinsically safe or non-incendive systems. A lot of API 670 compliant sensor setups use this configuration.
Q6: How does the 330851-04-000-023-10-01-05 prevent oil leakage through the cable?How does the 330851-04-000-023-10-01-05 stop oil from leaking through?
A: Bently Nevada uses something called FluidLoc® technology on this cable design. Basically, the inside of the cable is sealed in a way that stops oil or process fluid from traveling through the cable itself. On turbine systems, especially around lubrication oil areas, that matters more than people think because fluid migration can eventually affect the rest of the 3300 XL transducer system or the monitoring side electronics.