🌱 Moisture of solid fertilizers and liming materials — drying at 105 °C — PN-EN 12048

Physicochemistry PN-EN 12048

Overview

WHAT THIS TEST IS — SCOPE FROM THE PKN CARD, IN FULL: "Określono wagową metodę oznaczania zawartości wilgoci z suszeniem w temperaturze (105+-2) stopni C w odniesieniu do nawozów stałych i środków wapnujących" [A gravimetric method for the determination of moisture content by drying at a temperature of (105+-2) degrees C is specified for solid fertilizers and liming materials].

FOR WHICH PRODUCTS — AND FOR WHICH NOT (clause 1 of the text of EN 12048:1996). The method is applicable to silicate and carbonate liming materials and to phosphate fertilizers: superphosphates, natural rock phosphates, ground rock phosphates and partially solubilized rock phosphates. It is NOT applicable to hydrated and burnt lime, to ammonium compounds or to magnesium sulfates. This exclusion matters when placing an order: in accreditation scopes the subject of the test is most often given generally as "wapna nawozowe" [agricultural limes] — and the standard explicitly excludes burnt and hydrated lime.

PRINCIPLE (clause 3): drying of the sample at (105 ± 2) °C for 5 h and determination of the loss in mass.

PROCEDURE — THE WHOLE METHOD FITS ON TWO PAGES (clauses 4–8): • desiccant: silica gel with indicator, grain size 2 mm to 5 mm, activated just before use — about 100 g in an evaporating dish for 2 h in an oven at 105 °C, then in a desiccator until cool; • laboratory sample WITHOUT GRINDING (according to EN 1482); if necessary, crush it quickly — do not grind it — in a mortar, mix all the material and take the test portion at once; Note 1 recommends crushing in an atmosphere with a relative humidity of 40 % to 60 %; • the weighing bottle (diameter 70 mm to 80 mm, with a stopper) is dried for 2 h at 105 °C and cooled in a desiccator; about 10 g of the sample is weighed into it to the nearest 0.001 g; • the open weighing bottle with the sample and the stopper are dried for 5 h at 105 °C, transferred to a vacuum desiccator and cooled to ambient temperature; after opening the desiccator, the bottle is quickly closed with the stopper and weighed to the nearest 0.001 g. RESULT (clause 8): moisture content as a percentage by mass = (m₀ − m₁) / m₀ × 100, where m₀ is the mass of the test portion before drying and m₁ after drying. The result is the mean of at least two determinations, rounded to 0.1 % (m/m).

WHAT EN CHANGED IN ISO 8190 (endorsement notice in EN 12048:1996): the title and the scope were extended to liming materials; the reference to ISO 8358:1991 was replaced by EN 1482:1996 (clauses 2 and 6); in clause 9 a requirement was added to state the method of sampling and sample preparation in the test report; a bibliography was added (Annex ZA). That is why the PKN card gives "ISO 8190:1992 [MOD]".

EDITIONS (state of the PKN card on 25.09.2026). PN-EN 12048:1999 — Polish version, publication 09-12-1999, 7 pages, KT 156 Fertilizers; introduces EN 12048:1996 [IDT] and ISO 8190:1992 [MOD]; without the "Wycofana" [Withdrawn] header. At the publisher (the CEN catalogue run by iTeh, read on 25.09.2026): EN 12048:1996 published 30-09-1996; stage 90.93 — decision to confirm after the systematic review (enquiry from 08-07-2022, closing 23-09-2026).

HOW ACCREDITATION SCOPES CITE THE STANDARD. Measurement of 25.09.2026 on the database of PL accreditation scopes (1310 laboratories with entries): 20 entries at 15 laboratories; notation "PN-EN 12048:1999" (19) and once "PN-EN 12048:1999 M". The subject of the test is mostly agricultural limes and liming materials (among others "Wapna nawozowe" [Agricultural limes] — 4, "Wapna nawozowe zawierające magnez" [Agricultural limes containing magnesium] — 3); the methodology "Zawartość wilgoci" [Moisture content] (7), "Zawartość wody" [Water content] (4) and their variants; the technique "Metoda wagowa" [Gravimetric method] (18). The declared ranges have lower limits from 0.1 % to 1.0 %, and upper ones from 10.0 % to 95.0 %. THE SAME NUMBER, A DIFFERENT STANDARD: PN-EN ISO 12048:2002 is "Opakowania — Opakowania transportowe z zawartością — Metody badania odporności na nacisk statyczny" [Packaging — Transport packages with contents — Methods of testing the resistance to static pressure] (PKN card). Three laboratories have it in their scopes (notations "PN-EN ISO 12048:2002", "EN ISO 12048:2000", "ISO 12048:1994") — we do not count those entries here.

THE KEY OF THE "LABORATORIES" TAB: "PN-EN 12048" — 15 laboratories and 20 entries, without foreign entries; the packaging standard with the ISO element does not fall into the tab.

PRECISION (Annex A, informative). Repeatability limit r = 0.15 √m, reproducibility limit R = 0.6 √M, where m and M are the means of two results; the difference between two results may exceed the limit on average not more often than once in 20 cases. The data come from a 1982 study in 21 laboratories on samples of ammonium sulfate, natural rock phosphate and 18 % superphosphate (granular and powdered). The standard points out that in that study the samples were ground and sieved, whereas the published method provides only for crushing — which is why it gives the data "for information only". Ammonium sulfate was in the precision study, although ammonium compounds are excluded from the scope.

WHAT WE DO NOT GIVE. We read the text of EN 12048:1996 in full from the page images of the fragment made available by the publisher (scan: EN cover with the annotation "CORRECTED 1996-12-12", foreword with the endorsement notice, clauses 1–9, Annex A — precision, Annex ZA — bibliography). We do not give data that the standard does not contain: e.g. requirements for the balance beyond the 0.001 g readability.

Method principle

About 10 g of unground sample is dried in an open weighing bottle for 5 h at (105 ± 2) °C, cooled in a desiccator over activated silica gel and weighed to the nearest 0.001 g. Moisture content = (m₀ − m₁) / m₀ × 100 %; result — the mean of at least two determinations, to the nearest 0.1 %.

Applications

• Silicate and carbonate liming materials (among others carbonate agricultural limes)
• Phosphate fertilizers: superphosphates, natural rock phosphates, ground and partially solubilized rock phosphates
• Determination of moisture in the quality control of liming materials and phosphate fertilizers
• NOT for burnt and hydrated lime, ammonium compounds and magnesium sulfates

Key parameters

Standard

Standard number

PN-EN 12048:1999 (wersja polska; wprowadza EN 12048:1996 [IDT] i ISO 8190:1992 [MOD])

Title (PL)

Nawozy stałe i środki wapnujące — Oznaczanie zawartości wilgoci — Metoda wagowa z suszeniem w temperaturze (105 ± 2) °C

Title (EN)

Solid fertilizers and liming materials — Determination of moisture content — Gravimetric method by drying at (105 ± 2) °C

Step-by-step procedure

1. Activation of the desiccant

   About 100 g of silica gel in an evaporating dish — 2 h in an oven at 105 °C, then into the desiccator until cool.

   ⏱ Time: 2 h • 🌡 Temperature: 105 °C

2. Sample

   According to EN 1482, without grinding; if necessary, crush quickly in a mortar (Note 1: at a relative humidity of 40–60 %), mix all the material and take the test portion at once.

3. Weighing bottle

   Dry the weighing bottle for 2 h at 105 °C, cool it in the desiccator, weigh about 10 g of the sample into it to the nearest 0.001 g.

   ⏱ Time: 2 h • 🌡 Temperature: 105 °C

4. Drying

   The open weighing bottle with the sample and the stopper — 5 h in the oven at 105 °C.

   ⏱ Time: 5 h • 🌡 Temperature: (105 ± 2) °C

5. Weighing

   Transfer the bottle and the stopper to the vacuum desiccator, cool to ambient temperature, after opening the desiccator quickly close the bottle and weigh it to the nearest 0.001 g.

6. Result and test report

   Moisture = (m₀ − m₁) / m₀ × 100 %; mean of at least two determinations, to 0.1 % (m/m). The test report states, among other things, the method of sampling and sample preparation (requirement added in EN).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Handling hot vessels from the oven — heat-resistant gloves, tongs
• Dust of fertilizers and liming materials — crush briefly, wearing a dust mask for dusty materials
• Vacuum desiccator — check the condition of the glass before applying the vacuum

Frequently asked questions