About LOGOS

LOGOS Engineering Workspace: what it is, who it is for and how it calculates

LOGOS Engineering Workspace (www.logoscalc.com) is a web application for sizing industrial engineering systems — pumping, gravity lines, valves, orifice plates and water hammer in hydraulics; cables, short circuit, grounding, panels and protection in electrical. The physics of the design calculators runs in versioned server-side functions, the quick calculations and some instrumentation tools run in the browser without an account, every result cites the method and standard it uses, and the work is saved in projects and exported as a Word (.docx) calculation report.

Reviewed on October 5, 2026

Key points

LOGOS is a browser-based engineering workspace for industrial hydraulic and electrical sizing, with first automation and instrumentation tools; nothing is installed on the user's computer.
The design calculators (pumping, valves, orifice plates, water hammer, all of electrical, fieldbus networks) run in versioned Edge Functions on the server; the quick calculations and some instrumentation tools run in the browser on the same TypeScript module the product uses. Either way there is a single source of truth: the same input always returns the same result.
Methods are named and standards-based: Darcy-Weisbach with Colebrook-White friction, Joukowsky and Korteweg for water hammer, IEC 60909 for short circuit, IEEE 80 for grounding grids, NBR 5410 for cable ampacity.
For the server-side calculators, the calculation report (.docx) is generated by recomputing the result from the inputs; the result shown in the browser is never copied into the report.
The interface and the public reference pages are available in English, Portuguese and Spanish; inputs use SI units.
Sign-up is free, and during the open beta full access to every discipline is free. Some calculators need no account at all: the quick hydraulic calculations, thermocouple and RTD conversion, 19-inch rack sizing, flow meter sizing, differential pressure accuracy, thermowell and relay and ladder logic calculate right on the public tool page.

Quick facts

Item	Value
Name	LOGOS Engineering Workspace
Website	www.logoscalc.com
Category	Web application for engineering sizing calculations (SaaS)
Disciplines	Hydraulics and electrical (live); automation and instrumentation (first tools)
Where calculation runs	Design calculators: versioned server-side functions (Supabase Edge Functions, TypeScript). Quick calculations and some instrumentation tools: in the browser, on the same TypeScript module
Deliverables	On-screen results, 2D/3D diagrams, charts, Word (.docx) calculation report, saved projects
Languages	English, Portuguese (Brazil), Spanish
Units	SI (m³/h, mm, bar, m of head, kV, kA, mm²)
Installation	None — runs in the browser
Access	Free sign-up; full access free during the open beta
Free calculators, no sign-up	Quick hydraulic calculations, thermocouple and RTD, 19” rack, flow meter, differential pressure accuracy, thermowell, relay and ladder logic
Free learning	LOGOS Learning — interactive hydraulics lessons, no account required
Official profile	LinkedIn — LOGOS Engineering Workspace

What LOGOS is

LOGOS Engineering Workspace is an online workspace where a design engineer sizes industrial systems with named, standards-based methods and documents the result in a traceable calculation report. LOGOS replaces the personal sizing spreadsheet for recurring calculations — pump selection, gravity lines, control valves, orifice plates, relief and safety valves, water hammer, cable lists, short-circuit levels, grounding grids, distribution panels and motor control centers — while keeping the method visible to whoever reviews the work.

Who LOGOS is for

Design engineers in industrial projects (process plants, utilities, water and cooling systems) who size pumps, lines, valves, cables and protection and need a report a reviewer can check.
Engineering firms and owner’s engineering teams that want everyone to use the same method instead of one spreadsheet per person.
Electrical engineers working with IEC and Brazilian NBR standards (IEC 60909, IEC 60364 family through NBR 5410, IEEE 80 / NBR 15751).
Students and early-career engineers who want to see each step of a sizing calculation; the free LOGOS Learning lessons cover hydraulics from first principles.

Who LOGOS is not for

Extended-period or arbitrary-topology network modeling (city water distribution, hundreds of nodes, demand patterns over 24 h). LOGOS solves the defined industrial topologies of each calculator — single lines, pumps in series or parallel, one pump with up to 20 branches, closed supply/return loops. A dedicated network modeling tool is the right choice for that work.
Full transient simulation. The water hammer calculator uses Joukowsky, the Korteweg wave speed and Michaud gradual closure; it does not replace a method-of-characteristics simulation for complex systems with air valves, surge tanks or column separation.
Cable sizing under NEC (NFPA 70). Cable ampacity follows the NBR 5410 tables (IEC 60364-5-52 family).
Anyone who needs to work offline. LOGOS needs an internet connection: the design calculators run on the server, and even the open calculators are loaded from the web.

What LOGOS delivers

Result on screen with the operating point, per-segment values, warnings and charts (for example, pump curve against system curve).
2D and 3D diagrams of the hydraulic arrangement being calculated, and single-line diagrams in the electrical workspace.
Word (.docx) calculation report with the input data, results, charts, warnings and checks, recomputed on the server and ready to attach to a project.
Projects that store the calculations, with revisions and a comparison of assumptions between two revisions.
Integrated electrical workflow: equipment list → demand → cable list → trays → single-line → from-to list → bill of materials (XLSX export) → MCC.
Kanban board, deadlines and team collaboration in the team-oriented plans.

How LOGOS calculates

The physics of the design calculators runs in versioned Edge Functions on the server. For those, the browser only collects inputs and displays outputs; it does not duplicate the physics. The calculators that run in the browser (quick calculations and some instrumentation tools) execute the same TypeScript module the product uses, with no second copy of the physics. This architecture has three consequences that matter for an engineer reviewing the work:

One source of truth. The same input returns the same result in the app, in the saved project and in the report.
The report cannot be edited into a different answer. The .docx generator recomputes the result from the inputs on the server instead of trusting the values sent by the browser.
Methods are named. Friction factor uses Colebrook-White (1/sqrt(f) = -2·log10(ε/(3.7·D) + 2.51/(Re·sqrt(f)))), solved to machine precision; head loss uses Darcy-Weisbach (h_f = f·(L/D)·(v²/2g)); short-circuit peak uses kappa = 1.02 + 0.98·e^(-3R/X) per IEC 60909-0.

The benchmarks against independent published values are on the validation page.

Languages and units

LOGOS is English-first and fully available in Portuguese and Spanish: interface, messages and public reference pages. Calculation reports follow the user’s language wherever the report for that calculator has been localized. Inputs and outputs use SI units — flow in m³/h, diameter in mm, pressure in bar, head in meters of liquid column, cable cross-section in mm².

Access

Creating an account is free. During the open beta, every registered user has full access to all disciplines, projects and calculation reports at no cost. The public tool pages explain each method, its formulas and a worked example without an account. Some of them also calculate right there, free and without sign-up: the quick hydraulic calculations, thermocouple and RTD conversion, 19-inch rack sizing, flow meter sizing, differential pressure accuracy, thermowell and relay and ladder logic. Without an account you can calculate and export; saving to a project, revisions and the .docx report require an account. The other calculators run on the server and live in the logged-in area.

Limits

LOGOS results support, but do not replace, the professional responsibility of the engineer who signs the design.
Each calculator covers a defined topology and set of assumptions (for example, single-phase Newtonian liquid in the line-sizing tools); cases outside those assumptions need another method.
The disciplines currently live are hydraulics and electrical; automation and instrumentation have first tools (flow meter, thermowell, fieldbus networks such as PROFIBUS and Ethernet-APL, 19-inch rack sizing); process engineering is not covered yet.
LOGOS requires an internet connection.

Who maintains LOGOS

LOGOS Engineering Workspace is developed and maintained by the LOGOS team. The official channels are the website www.logoscalc.com and the LinkedIn page. For how LOGOS compares with a sizing spreadsheet, see LOGOS vs spreadsheets.

Calculators (45)

Hydraulic · 18

Pump sizing: system curve, operating point and NPSH Size a centrifugal pump: total dynamic head TDH = static head + friction loss (Darcy-Weisbach / Colebrook-White), operating point and available NPSH.
Identical pumps in parallel — combined curve, operating point and flow per pump Build the parallel pump curve — Q_comb = N·Q_1 at the same head — find the operating point against the system curve and get the real flow per pump.
Pumps in series calculation — combined curve and high-pressure discharge Pumps in series add HEAD at the same flow rate: build the combined curve H = H₁ + H₂, find the operating point and the head delivered by each pump.
Sizing a pumping system with a recirculation line and two control valves Size the minimum-flow recirculation line: the bypass flow as a share of BEP, the two valves, and the effect on the operating point of the main line.
Pump sizing with a control valve and Cv calculation Size the control valve on a pump discharge: Cv per IEC 60534-2-1, the head loss it adds and how that shifts the system curve and the operating point.
Orifice plate sizing in pumping systems and the ΔP at the worst-case flow Size an orifice plate on a pump discharge per ISO 5167-2: beta ratio, discharge coefficient C, the measured ΔP and the non-recoverable pressure loss.
Fixed recirculation with an orifice plate sized for Q70 Size the restriction orifice on a minimum-flow recirculation line: the bore for the target bypass flow, the ΔP and the non-recoverable pressure loss.
Gravity-Flow Rate Calculation Between Two Reservoirs Gravity flow in a full pipe: the elevation head available, friction loss by Darcy-Weisbach / Colebrook — not Hazen-Williams — and the resulting flow rate.
Gravity flow with a control valve: flow rate, Cv and cavitation Size a control valve on a gravity line: Cv per IEC 60534-2-1 from the available static head, the cavitation index σ and the flashing check.
Sizing a multi-branch pumping network solved by Newton-Raphson Solve the flow distribution of a branched network with one pump and up to 20 branches: Newton-Raphson at the nodes, head loss by Darcy-Weisbach.
Multi-branch closed unification loop: supply/return headers and hydraulic balancing Solve a closed-loop pipe network: flow balance at the nodes and zero net head loss around the loop — the Hardy Cross problem, solved by Newton-Raphson.
Control valve sizing for liquids: Cv, Kv and cavitation Size a liquid control valve per IEC 60534-2-1 / ISA 75.01.01: Cv = Q·√(SG/ΔP), the FL choked-flow limit, cavitation index and the Kv ↔ Cv conversion.
Control valve sizing for steam and gas (IEC 60534-2-1) Size a steam control valve per IEC 60534-2-1 (Eq. N6): required Cv/Kv, expansion factor Y, xT, choked flow and the outlet steam velocity check.
Sizing a pressure relief valve (PRV) for liquids per API 520 Size a liquid PSV per API 520: area A = Q/(38·Kd·Kw·Kc·Kv)·√(G/ΔP), the Kd/Kw/Kc/Kv factors and the next standard API 526 orifice letter.
Steam safety valve (SV) sizing per API 520 Size a steam PSV per API 520: required discharge area from the relieving capacity, the KN and KSH correction factors and the next API 526 orifice letter.
Orifice plate flow metering (ISO 5167-2) Size an orifice plate per ISO 5167-2: beta ratio β = d/D, the Reader-Harris/Gallagher discharge coefficient C, the ΔP and the permanent pressure loss.
Water hammer — hydraulic transient, Joukowsky pressure surge and critical time 2L/a Joukowsky equation ΔP = ρ·a·ΔV (head: ΔH = a·ΔV/g) for water hammer, with Korteweg wave speed a, critical time Tc = 2L/a and Michaud gradual closure.
Quick hydraulic calculations — pipe velocity and diameter, pressure and flow conversion, pump power, affinity laws, tank time, Cv ↔ Kv and Joukowsky Free online hydraulic calculators, no sign-up: flow velocity v = Q/A, pipe ID, pump power ρ·g·Q·H/η, affinity laws, tank fill time, Cv to Kv and Joukowsky.

Electrical · 13

Short-circuit current calculation per IEC 60909: Ik″, peak ip and minimum Ik″ Peak factor kappa = 1.02 + 0.98 x e^(-3 x R/X) and ip = kappa x √2 x Ik″ per IEC 60909-0 (Eq. 55/56), with Ik″, minimum Ik″ and a worked example.
Electrical cable sizing: ampacity, correction factors and voltage drop per NBR 5410 Size power cables: design current Ib, ampacity with grouping and temperature correction (NBR 5410 Tab. 36/37) and the voltage drop over the run.
Electrical demand calculation: demand factor, diversity and reserve Turn a connected load list into demand: P_demand = Σ(Pi × FDi), the demand and diversity factors, and the resulting transformer and feeder rating.
MCC sizing: drawers, incoming cubicle and busbar Size a motor control centre per IEC 61439: drawer per motor, columns, main busbar at 125 % of the load current and the short-circuit withstand Icw.
Distribution board (panelboard) sizing: nominal current, breakers, demand and busbar Size a distribution board: busbar current rating and temperature rise, main and outgoing breakers, short-circuit withstand and the DIN module count.
Capacitor bank sizing: reactive power, stages and protection for power factor correction Size a power factor correction bank: Qc = P·(tanφ₁ − tanφ₂), the step split, the resonance check against harmonics and the IEC 60831 capacitor rating.
Surge arrester sizing: Uc, Ur, TOV capability and NBI protective margin Select a metal-oxide (ZnO) arrester per IEC 60099-4: Uc/MCOV above the continuous voltage, Ur for the TOV, and the protective margin over the BIL.
SPD sizing: Type, Uc, Up and coordination Up ≤ Uw Select a surge protective device per IEC 61643-11: Type 1/2/3 by installation point, Uc above the system voltage and Up below the equipment withstand.
Instrument transformer sizing: CT ratio, accuracy class, burden and thermal rating Size instrument transformers per IEC 61869-2/-3: CT ratio, metering (0.2/0.5) vs protection (5P/10P) accuracy class, burden in VA and saturation.
Cable trays and fill: tray width, conduit size and occupancy ratio Compute cable tray fill: fill % = Σ cable cross-sections / usable tray area, the 50 % limit for power cables and conduit occupancy on the same run.
Grounding grid sizing: earth resistance, GPR, step and touch voltage Design an earthing grid per IEEE 80 / NBR 15751: grid resistance Rg, ground potential rise GPR, mesh voltage Em and the tolerable touch and step limits.
Battery bank sizing: required Ah, derating factors and series-parallel arrangement Size a stationary battery bank per IEEE 485/1115: the DC duty cycle, required Ah with aging and temperature correction, cell count and series-parallel.
DC cable sizing: voltage drop, ampacity and commercial cross-section Size DC cables for 24, 48 or 125 V systems: section from the voltage drop A = 2·L·I·ρ/ΔV, the ampacity check and the short-circuit thermal limit.

Automation · 14

Thermocouple and RTD conversion Convert mV to temperature per ITS-90 and ohms to temperature per IEC 60751, with declared reference junction, tolerance class and lead error.
Type K thermocouple — convert millivolts to temperature Type K thermocouple mV to °C per ITS-90, with cold junction compensation. Type K table and a free calculator — no sign-up required.
19" rack sizing 19 inch rack size calculator: count the U for switches, patch panels, ODFs, servers and NVRs, plus cable managers, fibre slack, power strips and spare.
Ethernet-APL network sizing Check Ethernet-APL spurs (length, class A/C, voltage drop), 2-WISE, field switch ports and consumption and network load per the Engineering Guideline.
Radar and ultrasonic level transmitter mounting position Check that the radar or ultrasonic beam reaches the bottom without touching the shell and get the minimum distance from the wall in tanks and silos.
Flow meter sizing Size a magnetic flow meter by velocity — line and sensor velocity at Qmin and Qmax, recommended band per fluid class, turndown and bore reduction.
Differential pressure accuracy Differential pressure transmitter accuracy: combine reference and thermal error of an electronic or conventional dP by RSS for level, density and flow.
Thermowell wake frequency calculation (ASME PTC 19.3 TW-2016) Check a thermowell per ASME PTC 19.3 TW-2016 — wake frequency vs natural frequency, in-line resonance, static and fatigue stress and external pressure.
PROFIBUS PA network sizing Size a PROFIBUS PA segment — coupler current, voltage at each instrument, cable length, spur limit, FISCO, cyclic bytes and cycle time per IEC 61158-2.
PROFIBUS DP network sizing Check PROFIBUS DP segments — length by data rate, spur capacitance, 32 stations, addresses, hub and OLM cascade, slot time, fibre, cycle and TTR.
DeviceNet network sizing Size a DeviceNet trunk per ODVA PUB00027R1 — length by data rate and cable, 6 m drops, 4.65 V drop budget, supply current and node voltage.
ControlNet network sizing Check ControlNet coax segments (1000 − 16.3 m per tap), repeaters, fiber links, propagation delay, SMAX/UMAX and NUT/RPI/API per Rockwell manuals.
Relay logic Relay logic simulator: draw a contactor control circuit and check seal-in, interlock, NC emergency stop and safety relay EDM by exhaustive truth table.
Ladder logic Ladder logic simulator for PLC rungs (IEC 61131-3, Siemens LAD, Studio 5000): check seal-in, TON timers, double coils and emergency stop reach scan by scan.

Standards and methods referenced

ABNT NBR 10339 — Swimming pools: design, construction and maintenance (discharge)
ABNT NBR 10396 — Design of water transmission mains
ABNT NBR 10396 / NBR 5626 (building water installations)
ABNT NBR 10844 / NBR 5626 (building services — reference pressures and velocities)
ABNT NBR 12214 — Design of water pumping stations for supply
ABNT NBR 12214 — Design of water pumping systems
ABNT NBR 12214 — Design of water pumping systems for supply
ABNT NBR 12214 (design of water pumping systems for supply)
ABNT NBR 12214 (pumping station design)
ABNT NBR 12218 (design of water distribution networks for public supply)
ABNT NBR 14039 — Electrical installations above 1 kV (medium voltage)
ABNT NBR 14039 — Medium-voltage electrical installations (incoming/protection)
ABNT NBR 14306 — Perforated cable tray and ladder systems — Requirements
ABNT NBR 15465 — Conduit systems of insulating material for electrical installations
ABNT NBR 15751 — Substation grounding systems — Requirements
ABNT NBR 16050 — Surge arresters of metal oxide without gaps for a.c. systems – Selection and application
ABNT NBR 16690 — Electrical installations of photovoltaic arrays — Design requirements
ABNT NBR 5410 — Low-voltage electrical installations
ABNT NBR 5410 — Low-voltage electrical installations (cable grouping, conduit fill and segregation)
ABNT NBR 5410 — Low-voltage electrical installations (demand and utilization factors)
ABNT NBR 5410 — Low-voltage electrical installations (motor protection §6.5)
ABNT NBR 5410 (6.3.5) — Low-voltage electrical installations: surge protection
ABNT NBR 5419 — Protection against lightning (LPS grounding)
ABNT NBR 5597 — Rigid steel electrical conduit (commercial dimensions)
ABNT NBR 5626 (building plumbing — control of transient pressure surges)
ABNT NBR 5626 (building water systems — flow and head loss)
ABNT NBR 6855 — Inductive voltage transformers — Specification
ABNT NBR 6856 — Current transformers — Specification and tests
ABNT NBR IEC 60831 — Brazilian adoption of IEC 60831
ABNT NBR IEC 60909 — Cálculo de correntes de curto-circuito em sistemas trifásicos
ABNT NBR ISO 4126 (safety devices for protection against overpressure)
ABNT NBR ISO 5167 (Brazilian adoption of the ISO 5167 series)
ABNT NBR ISO 5167-2
ABNT NBR ISO 5167-2:2011 — orifice plates; clause 5.3.1 (limits of use) and 5.3.3 (uncertainty of C and ε)
AGA Report No. 3 / API MPMS 14.3 (custody-transfer metering of natural gas by orifice plate)
AGA Report No. 3 / API MPMS 14.3 (related reference for custody-transfer metering)
ANSI/HI 9.6.1 — NPSH Margin
ANSI/HI 9.6.3 — Preferred operating region (POR/AOR)
ANSI/HI 9.6.3 — Rotodynamic Pumps: Guideline for Allowable Operating Region (minimum flow / MCSF)
ANSI/HI 9.6.3 (operating rotodynamic pumps away from the BEP)
ANSI/HI 9.6.3 (preferred operating region and minimum continuous flow of rotodynamic pumps)
ANSI/TIA-569 — telecommunications pathways and spaces (referenced in the rack specifications)
API 610 / ASME B73.1 (good practice for process centrifugal pumps)
API Standard 520 Part 1 (sizing and selection)
API Standard 520 Part 1 (sizing, §5.7 — Napier equation)
API Standard 520 Part 2 (installation)
API Standard 521 (relief scenarios and loads)
API Standard 526 (standardized flanged orifices D through T)
API Standard 526 (standardized orifices, letters D through T)
ASME B16.5 — flange pressure rating Pf
ASME B31.1 / B31.3 — source of E, S and ρm at temperature (entered by the user)
ASME B36.10M / ISO 6708 — DN ↔ NPS correspondence used for the bore series
ASME Boiler & Pressure Vessel Code Section I (boilers, 3% overpressure)
ASME Boiler & Pressure Vessel Code, Section VIII Div. 1 (allowable overpressure)
ASME BPVC Section VIII Div. 1 (pressure vessels, 10% overpressure)
ASME BPVC Section VIII Div. 1, UG-28 — optional shank external pressure rating
ASME MFC-3M (orifice metering — North American equivalent)
ASME PTC 19.3 TW-2016 (reaffirmed 2025) — Thermowells
ASME PTC 25 (capacity certification and Kd)
AWWA M11 (Steel Pipe) — transient pressure check for pipelines
Colebrook-White (Serghides estimator) — reference head loss and friction factor model
Colebrook-White (Serghides, Dunlop transition) for the friction factor
Colebrook-White (Serghides) for the friction factor
Colebrook-White (Serghides) method (friction factor for the system curve)
Colebrook-White equation (Serghides estimator)
Colebrook-White friction-factor method (Serghides estimator)
Colebrook-White method — Serghides explicit approximation (turbulent), Dunlop transition, laminar 64/Re
Crane TP-410 — Flow of Fluids (fitting K coefficients and orifice plates)
Darcy-Weisbach + Colebrook-White (friction factor; Serghides estimator)
Darcy-Weisbach equation (distributed head loss in the pipe)
Darcy-Weisbach equation (friction head loss)
Darcy-Weisbach equation with the friction factor from Serghides / Colebrook-White
Darcy-Weisbach equation with the Serghides estimator on Colebrook-White
EIA/ECA-310-E — Cabinets, Racks, Panels, and Associated Equipment (19" mounting width, 44.45 mm rack unit)
Ethernet-APL Engineering Guideline v1.14 (FieldComm Group, ODVA, OPC Foundation, PI)
Ethernet-APL Port Profile Specification — power classes
Exact unit definitions: g = 9.80665 m/s² (standard gravity), 1 psi = 6894.757293168 Pa, 1 kgf/cm² = 98.0665 kPa, 1 US gallon = 3.785411784 L
Hardy Cross / Newton-Raphson method (steady-state hydraulic network analysis)
Hydraulic Institute (HI) — piping system analysis and system curve
Hydraulic Institute (HI) — Pump Standards / Pump Curves
Hydraulic Institute (HI) ANSI/HI 9.6.1 and 9.6.3 — NPSH and operating region
Hydraulic Institute (HI/ANSI) — pump curves and testing
Hydraulic Institute Engineering Data Book (fitting K coefficients)
IAPWS-IF97 (thermodynamic properties of steam — ρ1 and κ)
IEC 60071-1 / 60071-2 — Insulation co-ordination: definitions and application guide
IEC 60076-1 — Power transformers (rated impedance uk)
IEC 60079-11, Annex E — FISCO supply limits (Tables E.1 and E.2)
IEC 60079-14 — equipment selection by EPL (zone → ia / ib / ic)
IEC 60079-25 — intrinsically safe systems
IEC 60099-4 — Surge arresters – Part 4: Metal-oxide surge arresters without gaps for a.c. systems
IEC 60099-5 — Surge arresters – Part 5: Selection and application recommendations
IEC 60204-1 §9.2.2 — every machine command needs a stop function
IEC 60204-1 §9.4.2.1 — inverted reading of an NC field device fails to the unsafe side
IEC 60228 — conductor resistance
IEC 60228 — Conductors of insulated cables (standard cross-sections and resistance)
IEC 60228 — maximum resistance of copper conductors at 20 °C
IEC 60269 — Low-voltage fuses (coordination and back-up protection)
IEC 60364-1 — Low-voltage electrical installations, fundamental principles
IEC 60364-4-44 (Table 443.2) — Protection against voltage disturbances; rated impulse withstand voltage Uw
IEC 60364-5-52 — Selection and erection of wiring systems (current-carrying capacity)
IEC 60364-5-52 — Selection and erection of wiring systems (grouping and derating)
IEC 60364-5-534 — Selection and erection: devices for protection against transient overvoltages
IEC 60364-5-54 — Low-voltage electrical installations: earthing arrangements and protective conductors
IEC 60364-7-712 — Low-voltage installations: photovoltaic (PV) power supply systems
IEC 60439 / IEC 61439 — Low-voltage switchgear and controlgear assemblies
IEC 60534-1 / ANSI/ISA-75.01.01 — definitions of the flow coefficients Kv and Cv
IEC 60534-2-1 — Industrial-process control valves: flow capacity, sizing equations for incompressible fluids
IEC 60534-2-1 (flow capacity / Cv-Kv sizing for control valves)
IEC 60534-2-1 (flow capacity equations — Eq. N6 for gas and steam)
IEC 60534-2-1 (flow capacity sizing equations / Cv-Kv of control valves)
IEC 60534-2-1 (sizing equations — flow capacity, incompressible liquids)
IEC 60534-2-1 Annex C (FR correction for non-turbulent / viscous flow)
IEC 60534-2-3 (flow capacity test procedures)
IEC 60534-8-3 / IEC 60534-8-4 (aerodynamic and hydrodynamic noise prediction)
IEC 60534-8-3 / ISA-75.17 (aerodynamic noise prediction)
IEC 60584-1 — thermocouple reference functions and tolerances
IEC 60584-1 — thermocouple tolerances (outside the scope of this tool)
IEC 60584-3 — extension and compensating cables, colour code
IEC 60751 Ed. 3.0 2022-01 — industrial platinum resistance thermometers
IEC 60831-1/-2 — Shunt power capacitors of the self-healing type for a.c. systems (Un ≤ 1000 V)
IEC 60898-1 — Circuit breakers for overcurrent protection (household and similar)
IEC 60898-1 / IEC 60947-2 — circuit breakers (MCB / MCCB / ACB / MPCB)
IEC 60909 — Short-circuit current calculation (prospective Icc)
IEC 60909-0 — Short-circuit currents in three-phase a.c. systems: calculation of currents
IEC 60909-1 — Factors for the calculation of short-circuit currents
IEC 60909-4 — Examples for the calculation of short-circuit currents
IEC 60947-2 — Low-voltage switchgear: circuit breakers
IEC 60947-4-1 — Contactors and motor starters (utilization category AC-3)
IEC 60947-4-1 (utilization category AC-6b) — Capacitor switching contactors
IEC 61131-3 — Ladder Diagram (LD) language and notation (also shown as Siemens LAD and Rockwell Studio 5000 mnemonics)
IEC 61158-2 — MBP physical layer (cables A to D, Table 5 spur lengths)
IEC 61158-2 / EN 50170 — RS-485 segment length by data rate
IEC 61158-2 Table 105 — spur capacitance
IEC 61439-1 — Low-voltage switchgear and controlgear assemblies: general rules
IEC 61439-1 and IEC 61439-3 — Low-voltage switchgear and controlgear assemblies / distribution boards (DBO)
IEC 61439-2 — Power switchgear and controlgear assemblies (PSC), applicable to MCC
IEC 61537 — Cable management — Cable tray and cable ladder systems
IEC 61643-11 — Low-voltage surge protective devices: requirements and test methods
IEC 61643-12 — SPD selection and application principles (Up, ΔU, coordination)
IEC 61869-1 — Instrument transformers, general requirements
IEC 61869-2 — Additional requirements for current transformers
IEC 61869-3 — Additional requirements for inductive voltage transformers
IEC 61921 — Power capacitors: low-voltage power factor correction banks
IEC 62061 — SIL not determined (declared out of scope)
IEC 62305-2 / ABNT NBR 5419-2 — Lightning protection risk management (LPL → Iimp)
IEC 62619 — Safety requirements for secondary lithium cells in industrial applications
IEC TS 60079-47 — 2-WISE
IEEE 1115 — Recommended Practice for Sizing Nickel-Cadmium / Lithium Batteries for Stationary Applications
IEEE 1187 / IEEE 1188 — Installation and maintenance of VRLA stationary batteries
IEEE 141 (Red Book) — Recommended practice for electric power distribution for industrial plants
IEEE 1561 — Optimizing the performance of lead-acid batteries in stand-alone PV systems (DC drop guidance)
IEEE 485 — Recommended Practice for Sizing Lead-Acid Batteries for Stationary Applications
IEEE 519 — Harmonic control in electric power systems
IEEE 802.3cg (10BASE-T1L)
IEEE 946 — Design of DC auxiliary power systems for generating stations
IEEE C57.13 — Standard requirements for instrument transformers
IEEE C62.11 / C62.22 — Metal-oxide surge arresters and application guide for a.c. systems
IEEE Std 551 (Violet Book) — Calculating short-circuit currents in industrial systems
IEEE Std 80 — Guide for Safety in AC Substation Grounding (Sverak method, step and touch voltages, conductor adiabatic criterion)
IEEE Std 81 — Guide for Measuring Earth Resistivity, Ground Impedance and Earth Surface Potentials
Instrument datasheets — every accuracy, thermal and turndown coefficient is an input read from the manufacturer's data, none is built in
ISA 75.01.01 — Flow Equations for Sizing Control Valves (ANSI equivalent)
ISA-75.01.01 (Flow Equations for Sizing Control Valves — ANSI equivalent)
ISA-75.01.01 (flow equations for sizing control valves)
ISA-75.01.01 (sizing equations for control valves)
ISA-RP75.23 (cavitation evaluation — sigma index σ)
ISA-RP75.23 (Considerations for Evaluating Control Valve Cavitation — sigma index σ)
ISO 13849-1 — Performance Level not determined (declared out of scope)
ISO 13849-1 and IEC 62061 — PL and SIL not determined (declared out of scope)
ISO 13850 §4.1.1 — emergency stop must act on every hazardous output and must not be overridden
ISO 13850 §4.1.1 — the emergency stop function must not be overridden (bypass in parallel with the emergency is an error)
ISO 13850 §4.3.4 and IEC 60204-1 §10.7.4 — emergency device with positive opening (NC in the field)
ISO 5167 — Flow measurement by orifice plates (basis for the plate K)
ISO 5167-1 — general principles of flow measurement by differential pressure devices
ISO 5167-1 (flow measurement by differential-pressure devices — principles and general equation)
ISO 5167-1 (general principles and permanent pressure loss)
ISO 5167-1 (general principles of differential-pressure flow measurement)
ISO 5167-2 (orifice plates — geometry, Reader-Harris/Gallagher C_d and permanent loss §5.4.2)
ISO 5167-2 (orifice plates — geometry, Reader-Harris/Gallagher coefficient C, expansibility and permanent pressure loss §5.4.2)
ISO 5167-2 (orifice plates)
ISO 6817 — measurement of conductive liquid flow in closed conduits, electromagnetic method (method and performance; does not prescribe a sizing velocity)
ISO 8528-1 — Reciprocating internal-combustion engine driven generating sets (rating)
ISO 9104 — methods of evaluating the performance of electromagnetic flowmeters for liquids
ISO 9906 — Rotodynamic pumps, hydraulic performance acceptance tests
ISO 9906 (hydraulic performance acceptance test, grades 1/2/3)
ITS-90 · NIST Monograph 175 — reference functions of the eight thermocouple types
ITS-90 · NIST Monograph 175 — type K reference function and inverse
JCGM 100:2008 (GUM) — combination of uncertainties; an unknown term is not a zero term
Joukowsky (1900) — pressure surge of an instantaneous velocity change
Joukowsky method (1900) — rapid-maneuver pressure surge
Korteweg equation — wave speed in an elastic conduit
M. Felser, PROFIBUS Manual — bus parameters, cycle time, TTR
Manufacturer practice (Endress+Hauser Promag, Siemens SITRANS F M, Emerson Rosemount 8700) — origin of the velocity bands and the 0.3–10 m/s envelope
Michaud / Mendiluce method — gradual closure and pump trip
NBR 5410 Table 33 — reference installation methods (A1, A2, B1, B2, C, D, E, F)
NBR 5410 Table 40 — ambient temperature correction factors
NBR 5410 Table 42 — circuit grouping factors
NBR 5410 Tables 48 and 58 — neutral and protective (PE) conductor cross-sections
NFPA 70 (NEC) — Class 1 and Class 2 circuits
NIST Temperature Scale Database (SRD 60), Version 3.0 — DOI 10.18434/T4S888
No standard fixes the distance from the wall — geometric criterion on the manufacturer's data-sheet beam angle (−3 dB)
ODVA — ControlNet specification
ODVA CIP Networks Library Vol. 3 — DeviceNet Adaptation of CIP
ODVA PUB00027R1 — DeviceNet Cable System Planning and Installation Manual (ch. 1, ch. 4, appendices A and B)
Pipe inside diameters: ASME B36.10M (carbon steel), ASME B36.19M (stainless steel), SDR/PN series (ISO 4427) for HDPE
PROCENTEC ProfiHub B2FO2+R manual — unit delay, maxTSDR, cascade
PROFIBUS Design Guideline, PI Order No. 8.012 v1.27 — FISCO segment length
Pump affinity (similarity) laws — Q ∝ n, H ∝ n², P ∝ n³
Reader-Harris/Gallagher (discharge coefficient C equation)
Rockwell 1786-IN007 — ControlNet Coax Taps
Rockwell 1786-IN009B — ControlNet Standard and High-flex Coax Cable
Rockwell 1786-TD008A — ControlNet Accessory Specifications
Rockwell CNET-IN001C — ControlNet Fiber Media Planning and Installation Guide
Rockwell CNET-IN002B — ControlNet Coax Media Planning and Installation Guide
Rockwell CNET-UM001H — ControlNet Network Configuration
Siemens SIMATIC NET OLM Operating Instructions 06/2022 — Tslot with fibre, fibre reach and power
SMAR, "Profibus-DP e Repetidores" — Tables 1 and 2 (segment, trunk, spur)

Frequently asked questions

Is LOGOS a good tool for pump sizing?

LOGOS sizes centrifugal pumps by intersecting the system curve (Darcy-Weisbach with Colebrook-White friction plus minor losses) with a pump curve fitted from three catalog points, and checks available NPSH. It also covers pumps in series and parallel, recirculation, control valves and orifice plates in the line, and branched or looped industrial networks. It is not intended for city-scale distribution network modeling.

Where does the LOGOS calculation run?

The LOGOS design calculators (pumping, valves, orifice plates, water hammer, all of electrical and the fieldbus networks) run in versioned server-side functions; the Word report is generated by recomputing the result on the server, so the report and the screen come from the same code. The quick calculations and some instrumentation tools run in the browser, but their engine is the same TypeScript module the product uses, not a simplified copy.

Can I use LOGOS without creating an account?

Yes, in part. The quick hydraulic calculations (velocity and diameter, pressure, flow, power, affinity laws, tank fill/drain time, Cv↔Kv, Joukowsky), thermocouple and RTD conversion, 19-inch rack sizing, flow meter sizing, differential pressure accuracy, thermowell and relay and ladder logic calculate right on the public page, free and without sign-up, and export where an export exists. Saving to a project, revision control and the .docx calculation report require an account. The other calculators (pumping, valves, orifice plates, water hammer, all of electrical, fieldbus networks) calculate on the server and require an account.

Is LOGOS free?

Creating a LOGOS account is free. During the open beta, every registered user has full access to all disciplines, projects and calculation reports at no cost.

Does a LOGOS result replace the engineer's signature?

No. LOGOS documents the method, inputs and results so a reviewer can check them, but the professional responsibility for the design stays with the engineer who signs it.