Calculated Results
Results appear here after submission and remain above the calculator form.
Corrected Titrant Volume
Total Exchange Capacity
Dry Resin Mass
Capacity on Wet Basis
Capacity on Dry Basis
Volumetric Capacity
Batch Bed Capacity
Operating Capacity
Target Ion Loading
Calculator Inputs
Use laboratory titration data and resin condition values to estimate exchange performance.
Example Data Table
This worked example shows how typical laboratory measurements translate into wet-basis and dry-basis capacity values.
| Parameter | Example Value | Unit | Why It Matters |
|---|---|---|---|
| Wet sample mass | 10.00 | g | Reference mass for wet-basis capacity. |
| Moisture content | 50.00 | % | Converts wet mass to dry mass. |
| Active purity | 98.00 | % | Removes inert fraction from the estimate. |
| Titrant normality | 0.10 | eq/L | Defines equivalents delivered per liter. |
| Sample titrant volume | 185.00 | mL | Measured consumption during titration. |
| Blank volume | 5.00 | mL | Corrects reagent background use. |
| Calculated dry-basis capacity | 3.673 | meq/g | Typical resin specification style. |
Formula Used
1) Corrected titrant volume
Vcorr = Vsample − Vblank
Blank subtraction removes titrant consumption unrelated to ion exchange.
2) Total exchange milliequivalents
meqtotal = N × Vcorr × D
Because 1 eq/L × 1 mL = 1 meq, normality multiplied by milliliters gives milliequivalents directly.
3) Effective dry mass
mdry = mwet × (1 − moisture/100) × (purity/100)
This adjusts wet resin mass for moisture and inactive material.
4) Capacity values
IECwet = meqtotal / mwet
IECdry = meqtotal / mdry
Capacityvol = IECwet × bulk density
5) Bed and operating capacity
Bed capacity = Capacityvol × Bed volume
Operating capacity = Bed capacity × (regen efficiency/100) × (1 − safety factor/100)
How to Use This Calculator
- Choose the resin type for your recordkeeping.
- Enter wet sample mass, moisture content, and active purity.
- Input titrant normality, sample titrant volume, and blank volume.
- Apply any dilution factor used during sample preparation.
- Select target ion valence to convert meq into mmol loading.
- Provide bulk density and bed volume for volumetric estimates.
- Enter regeneration efficiency and safety factor for practical operating capacity.
- Press Calculate Capacity to show the results above the form.
- Use the CSV or PDF buttons to export the computed summary.
Frequently Asked Questions
1) What does ion exchange capacity mean?
It measures how many exchangeable ionic sites a resin provides. Laboratories often report it in milliequivalents per gram or per milliliter.
2) Why calculate both wet-basis and dry-basis capacity?
Wet-basis capacity reflects the resin as handled. Dry-basis capacity removes moisture effects and is better for comparing specifications, production lots, or suppliers.
3) Why is blank correction important?
Blank correction removes titrant used by reagents, glassware residue, or procedural background. Without it, calculated capacity can be overstated.
4) What does normality contribute to the formula?
Normality expresses equivalents of reactive charge per liter. Multiplying it by corrected titrant volume directly gives total milliequivalents exchanged.
5) Why include active purity in the dry-mass calculation?
Purity removes inert binder, contamination, or off-spec material from the active resin mass. This gives a more realistic dry-basis capacity.
6) How does target ion valence affect loading?
Higher-valence ions consume more exchange charge per mole. Dividing dry-basis meq/g by valence converts charge capacity into mmol/g loading.
7) What is operating capacity used for?
Operating capacity estimates practical performance after regeneration losses and design margin. It is useful for sizing beds, regeneration plans, and service-cycle targets.
8) Can this calculator replace a standard test method?
No. It organizes calculations from your test data. You should still follow your laboratory method, resin specification sheet, and site validation requirements.