Level Capacitance Type

IPE Engineering Practice IPE-EP-12-1-17

Document number: IPE-EP-12-1-17 · Section: 12 — Instruments and Controls

SCOPE

Capacitance type level instruments shall be supplied in strict accordance with the Data Sheet EP 12- 1-17 DS, this Practice, and the referenced standards and publications.
Where special features or improvements over the Practice are required as determined by the Owner, or Owner’s Engineer, these shall be specified on the Instrument Data Sheets and shall be adhered to by the Vendor.
Any deviation from this Practice must be approved by the procedure described in EP 1–1–3.
A revision bar indicates all changes made to this Revision.

2.0 REFERENCES

The following codes and standards shall be considered as part of this Practice. All documents shall be the latest editions in force on the date of issuance of this Practice.

STANDARDS AND PUBLICATIONS

IPE Engineering Practices
EP 1–1–3 Deviations to IPE Engineering Practices EP 12–1–1 Control Systems EP 12–1–2 Supplemental Requirements for Control Systems EP 12–1–17 DS Level Capacitance Type Data Sheet
ASME
B 1.20.1 Pipe Threads General Purpose (Inch)
NEMA
ICS 6 Enclosures for Industrials Controls and Systems
NFPA
70 National Electrical Code
SAMA
PMC 33.1 Electromagnetic Susceptibility of Process Control Instrumentation

DEFINITIONS

Contractor - Company or business that agrees to furnish materials or perform specified services at a specified price and/or rate to the Owner.
Inspector - A Inflection Point Engineering, LLC . appointed engineer or inspector.
Manufacturer - The recipient of a direct or indirect purchase order for materials and/or equipment. In this context, a direct order is one issued to a manufacturer by a contractor or the Owner. An indirect order is one issued to a manufacturer by a vendor (recipient of a direct order) for materials, fabricated components, or subassemblies.
Owner - Inflection Point Engineering, LLC .
Owner’s Engineer - A Inflection Point Engineering, LLC. appointed engineer.
Purchaser - The party placing a direct purchase order. The purchaser is the Owner’s designated representative.
Vendor - Recipient of a direct purchase order.

DESIGN AND MATERIALS

General
Instruments shall be RFI immune. Manufacturer shall test equipment per SAMA Standard, PMC 33.1. Instruments shall be affected by no more than 1% of span when exposed to a field strength of 10 volts per meter (Class 2) with a frequency range of 50-500 MHZ (bands b and c).
Electrical equipment shall be suitable for operation in the National Electric Code (NEC) Class 1, Group B, C, and D, Division 2 area classifications unless otherwise specified on the Data Sheet.
Design and materials not specified shall be in accordance with the manufacturer’s standards for the operating and design conditions specified on the Data Sheet.
Probe

Material, connection type, and insertion length shall be as specified on the Data Sheet.

Transmitter
Electronic transmitter output shall be 4-20 mA DC.
Transmitter shall be powered by 24 V DC.

4.4 Switches

Switches shall be as specified on the Data Sheet.

INSTRUCTIONS FOR DATA SHEET

Show meter tag number
Refers to process service or application
Give line number or process area
Specify solids level, liquid level, interface, foam detection.

Specify alarm, transmit, on-off control, etc.
Specify high, low, none
Specify if probe axis is horizontal, vertical, etc.
Specify general purpose, heavy duty, knife-blade, inline plate, concentric shield, etc.
Specify probe material
Specify sheath, if required, (1/4 in teflon, etc.)
Specify total immersion in inches, or feet and inches.

12 Specify length of inactive extension in inches, or feet and inches.

Specify sealing gland material and size (316 SS, 3/4 in NPT, etc)
Specify conduit connection (3/4 in. NPT, 7/8 in OD knockout, etc)
Specify if electronics are mounted at probe or remotely located.
Specify enclosure electrical classification (general purpose, NEMA 4X, Explosion proof, etc)
Specify conduit connection (3/4 in. NPT, 7/8 in OD knockout, etc)
Specify power input (115 VAC, 60 HZ)
Specify switch type as mercury bottle, snapaction, etc.
Specify number of switches and contact form of each switch. ( SPST, SPDT, DPDT, etc.)
Specify switch voltage (115 VAC, 60Hz, 24 VDC, etc)
Specify contact rating in amps/watts
Specify load as inductive or non-inductive

26-27. Specify if contacts open or close when the level increases or decreases.

Specify transmitter output(4-20 mA, etc)
Specify level range in inches or feet and inches corresponding to minimum and maximum transmitter signal.
Specify enclosure electrical classification (general purpose, NEMA 4X, Explosion proof, etc)
Specify length of special compensating cable to be furnished with probe, if required.
Specify size, type, and range of local indicator, if required.
Specify if electro–pneumatic transducer (3-15 psi) is required.
Specify if high, low, hi/lo, lights are required and rating.
Specify upper fluid by name and state (liquid, vapor)
Specify dielectric constant of upper fluid
Specify lower fluid by name and state (liquid, vapor)
Specify dielectric constant of lower fluid
Specify maximum and normal operating pressure at the probe.
Specify maximum and normal operating temperature at the probe.
Specify percentage moisture content of solids.
Specify if material is expected to build up on probe.
Specify vibration environment of probe (mild, severe) 48-51. Fill in manufacturer and model numbers after selection.

© 2026 Inflection Point Engineering, LLC. All rights reserved. The content of this page — including calculation methods, reference data, written analysis, interactive tools, and source code — is the intellectual property of Inflection Point Engineering, LLC and is protected under applicable copyright, trademark, and trade secret laws. Unauthorized reproduction, redistribution, modification, or derivative use in whole or in part is prohibited without prior written consent.

Disclaimer. This material is provided for informational and educational purposes only and does not constitute professional engineering advice. Calculations, reference data, and methodologies are based on published standards and accepted engineering practice but are not a substitute for engineering judgment, site-specific analysis, or review by a licensed Professional Engineer. Inflection Point Engineering, LLC makes no warranties, express or implied, regarding the accuracy, completeness, or fitness for a particular purpose of any content presented here, and shall not be liable for any direct, indirect, incidental, or consequential damages arising from its use. Users assume all risk associated with applying this content to real-world design, operations, or decisions.