Engineering tools

Field calculators, from our own toolbox.

Tools we built for our own commissioning work and use on site.

Tool 01

Charge injection calculator

Vibration level to pC and back, for checking a vibration monitor without shaking the sensor.

Check a vibration monitor without shaking the sensor. A piezoelectric accelerometer delivers a charge (pC) proportional to acceleration, so with a charge generator (Coulomb simulator) you inject that charge straight into the monitor input at the 1X frequency of the machine. This tool converts a vibration level at running speed into the peak charge to inject, and an injected charge back into the reading you should see.

Level and speed

Enter the vibration level to simulate (an alarm or trip setpoint, as displacement or velocity) and the running speed of the machine.

Sensor sensitivity

Enter the sensitivity of the accelerometer in pC/g, from its datasheet or calibration sheet.

Inject and compare

Set the charge generator to the pC and the frequency shown in the result, then compare the monitor reading. Monitors with a tracking filter or keyphasor also need a speed signal: simulate it at RPM ÷ divisor.

A

Vibration level → charge to inject

pC/g
From the datasheet
Inject
Charge input — pC Speed input
Peak value. pC = velocity × 2π × f × sensitivity / 9810
B

Injected charge → expected reading

pC
pC/g
From the datasheet
Expected
Monitor reads — mil Charge input Speed input
velocity = pC × 9810 / (2π × f × sensitivity) · displacement = velocity / (2π × f)
Background: 1X, speed signal divisor, formulas
Running speed and 1X: unbalance shows up once per revolution, so the charge is injected at the 1X frequency: RPM ÷ 60 Hz. That is the frequency to set on the charge generator. Enter the speed in RPM, or switch to Hz to enter the frequency of the speed signal instead.
Speed signal divisor (RPM : Hz): how many RPM one Hz of the speed pickup signal represents: 60 ÷ teeth on the speed wheel, times the gear ratio if the wheel sits on another shaft. A 60-tooth wheel gives 1 (3000 RPM = 3000 Hz), 47 teeth gives 1.277 (9000 RPM = 7050 Hz), a one-pulse-per-rev keyphasor gives 60 (3000 RPM = 50 Hz). Only matters when you simulate the speed input of the monitor as well, or enter the speed as a signal frequency. The 1X frequency for the charge generator stays RPM ÷ 60.
Charge output: the result is peak pC (not peak-to-peak), the standard for piezoelectric accelerometer charge injection calibration.
pC = (velocity [mm/s] × 2π × f [Hz] × sensitivity [pC/g]) / 9810
Unit conversions:
1 mil = 0.0254 mm = 25.4 μm | RPM ÷ 60 = Hz
Displacement ↔ velocity: v = d × 2πf
Peak ↔ peak-to-peak: multiply or divide by 2
Tool 02

Woodward manuals and software finder

Search woodward.com directly, or start from the document numbers for MicroNet, 505, 5009FT, ProTech and easYgen.

Woodward publishes its manuals, product specifications and service tools on its own site. Search there directly, or start from the document numbers we use most. Each number opens Woodward's search for it, with the current revision and the other languages.

MicroNet, MicroNet Plus and MicroNet TMR What we do on these systems →

NumberTitleType
26166 V1–V3MicroNet Simplex / MicroNet Plus digital controlTechnical manual
26167 V1–V3MicroNet TMR digital controlTechnical manual
03333MicroNet Plus control systemProduct specification
26479MicroNet Plus cyber security manualCyber security bulletin
26728SIL safety manual (MicroNet)Technical manual
03375MicroNet Safety ModuleProduct specification

Steam turbine controls: 505, 505XT, 5009FT, Peak 200 What we do on these systems →

NumberTitleType
26839 V1–V2505 digital control for steam turbinesTechnical manual
35018 V1–V3505XT digital control for steam turbines (single valve, extraction and/or admission)Technical manual
26518 V1–V45009FT fault-tolerant steam turbine controlTechnical manual
033735009FT fault tolerant controlProduct specification
35051Peak200 digital control for steam turbinesTechnical manual
03438Peak200 digital control for steam turbinesProduct specification

Overspeed protection: ProTech What we do on these systems →

NumberTitleType
26545ProTech-GII overspeed protection deviceTechnical manual
26709ProTech-GII overspeed protection device with voted inputsTechnical manual
03370ProTech-GII overspeed protection deviceProduct specification
85206ProTech 203 (no interposing relay)Technical manual
26712ProTech GAP manualTechnical manual

Generator controls: easYgen and LS-6XT What we do on these systems →

NumberTitleType
B37574easYgen-3100XT/3200XT-P1 technical manualTechnical manual
B45027easYgen-3000XT series product specificationProduct specification
B37913easYgen | LS-6XT product specificationProduct specification

Service tools

NumberTitleType
AppManagerAppManager service tool (current and legacy versions)Software
Control AssistantControl Assistant service tool (current and legacy versions)Software
26015Woodward Control Assistant software, getting startedTechnical manual
26775Using Control Assistant & SOS software in place of Watch Window & Servlink softwareTechnical manual

Good to know. Woodward splits the bigger manuals into volumes (V1, V2 ...), so search on the number without the volume to see them all. The part number on the control's nameplate or the application number in AppManager is often the quickest way to the right document. Documents and software stay on woodward.com; we only link to them. Finder as a separate page →

Tool 03

Thermocouple calculator

Temperature to mV and back for type K, J, E and T, with the reference junction taken into account.

Check a thermocouple input with a mV source, or turn a measured mV into temperature. The tables are referenced to 0 °C, while the input card compensates for the temperature at its own terminals. So the mV to source is the table value at the process temperature minus the table value at the terminals.

A

Temperature → mV to source

Reference junction at the input card
Source
mV source — mV Table value —at 0 °C reference
mV to source = E(process) − E(terminals). NIST ITS-90 reference functions (IEC 60584-1).
B

Measured mV → temperature

mV
Where the mV is measured
Process temperature
Reads — °C Also —
E(process) = measured mV + E(terminals), then back to temperature.
Background: calibrators, test leads, types
Calibrator in thermocouple mode. Dial the process temperature and let the calibrator compensate (CJC on). Use this calculator when you source plain mV, or check a reading with a multimeter.
Where to connect. Source the mV at the card terminals with copper test leads, and take the terminal temperature there. Most control systems also show the card's own reference junction temperature.
Ranges. Type K −270 to 1372 °C, J −210 to 1200 °C, E −270 to 1000 °C, T −270 to 400 °C.
Colours. IEC and ANSI use different cable colours for the same type. Check the type on the sensor or the datasheet, not on the cable.
Tool 04

4–20 mA calculator

Scale a loop current both ways, with the five check points for a loop check.

Scale a 4–20 mA signal both ways for a linear transmitter, and get the 0, 25, 50, 75 and 100 % check points for the loop check sheet.

A

Process value → mA

At 4 mA
At 20 mA
Signal
Loop current — mA Of span —
mA = 4 + 16 × (value − LRV) / (URV − LRV)
B

Measured mA → process value

mA
Same range as card A
Process value
Reads — Of span —
value = LRV + (URV − LRV) × (mA − 4) / 16
Check points
SpanCurrent (mA)Value
Background: NAMUR NE 43 signal levels
Measuring range. 3.8 to 20.5 mA carries a measurement. Between 3.8 and 4 mA and between 20 and 20.5 mA the transmitter is saturated: below or above its range, but not failed.
Failure signal. 3.6 mA or less, or 21 mA or more, means the transmitter reports a fault. Check which way your transmitter is set to drive on failure.
Linear signals only. For a DP flow transmitter with square-root extraction in the control system, the mA to flow relation is not linear.
Reverse ranges. A lower range value above the upper one works too, for example 100 to 0 % valve position.
Tool 05

Pt100 calculator

Resistance to temperature and back for Pt100, Pt500 and Pt1000 sensors.

Check an RTD input with a decade box, or turn a measured resistance into temperature. For standard platinum sensors to IEC 60751 (alpha 0.00385).

A

Temperature → resistance

Set the decade box to
Resistance — Ω
R = R0 × (1 + A·t + B·t²), below 0 °C + C·(t − 100)·t³
B

Resistance → temperature

Ω
Temperature
Reads — °C Also —
A = 3.9083e-3, B = −5.775e-7, C = −4.183e-12 (IEC 60751)
Background: lead resistance and wiring
2-wire inputs. The cable resistance adds to the reading: about 2.6 °C per ohm on a Pt100. Source the resistance at the sensor end of the cable, or subtract the loop resistance.
3- and 4-wire inputs. These compensate the leads. Connect the decade box with all wires, so the input sees the same wiring as with the sensor.
Tool 06

Compressor efficiency and fouling check

LM2500, LM6000 or any axial compressor: efficiency from your own readings, compared with a baseline you keep.

Is the compressor getting dirty, and did the wash help? Take a few readings right after a wash and save them as a baseline. Next time, load that file: the tool tells you which speed to run for each step at today's inlet temperature, and compares efficiency and pressure ratio at the same corrected speed. Save every later check too, clean or dirty, and you build up a history of the engine.

Baseline

Right after a wash, overhaul or new install: enter readings at 3 to 5 steady load steps and save them. The file stays on your own pc.

Same speed

Later: load the file. For each step you see the speed to run at today's inlet temperature. Set the load, let it settle.

Compare and keep

Enter today's readings and see the change against the baseline. Save them as a check: load all files next time and you see the trend.

1

Engine and units

Checked against the baseline
Inlet and interstage
Needed with gauge pressures
2

Saved files if you have them

Load the baseline saved after the last wash or overhaul, plus earlier checks if you want the history. You can select several files at once. No files yet? Go to step 3 and save today's readings as the first baseline.

3

Readings

Steady state only: no SPRINT, no anti-icing, no load change in the last minutes. One row per load step. Row 1 holds example values: overwrite them with your own.

Reading 1
Isentropic efficiency
—%
No baseline loaded
Polytropic
—
Pressure ratio
—
Corrected speed
—
4

Results

ReadingSectionCorr. speed rpmPRIsentropic eff. %Polytropic eff. %Δ eff. vs base, ptsΔ PR vs base %Against baseline
Dirty or clean, every check can be saved
Saved in the file

Background: method, accuracy and what it does not tell you
Method. Dry air as an ideal gas with a temperature-dependent cp, so no constant gamma. With a constant gamma of 1.4 the efficiency reads 2 to 4 points too high at LM pressure ratios.
η isentropic = (h(T2s) − h(T1)) / (h(T2) − h(T1))
Same corrected speed. Efficiency changes with load and with the variable stators, so a reading is only compared at the same corrected speed: N / √(T inlet / 288.15 K). The speed to run today is that corrected speed times √(T inlet today / 288.15 K). On the LM6000 the LPC uses N2 and T2, the HPC N25 and T25.
Trend, not a spec value. A thermocouple error of 1 °F moves the result by roughly 0.1 to 0.15 point, and the discharge pressure is a static pressure. The number itself is not an OEM performance figure; the change against your own baseline is what counts.
What to leave out. SPRINT, anti-icing or inlet heating, open bleed or VBVs, starts and load changes. After an engine change or a new inlet or discharge sensor, make a new baseline.
Reading the result. Fouling shows as lower efficiency and a lower pressure ratio at the same corrected speed. If a wash brings both back, it was dirt. If not, look further: sensors, bleed, stator schedule or damage.
Your data. Everything is calculated in your browser and the baseline is saved to your own pc. Nothing is uploaded. Humidity is not included; that is a small effect for trending.
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Tools for authorised users

LM2500+G4 and LM5000 tools built on OEM data, with a personal login.

Two more tools are built on OEM data: the LM2500+G4 4B bearing HP recoup orifice tool and the LM5000 VG schedule verification tool. They are available to persons authorised by the OEM, with a personal login.

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