ISO 4112:2025

International
Standard
ISO 4112
Third edition
Cereals and pulses — Guidance on
2025-06
measurement of the temperature of
grain stored in bulk
Céréales et légumineuses — Directives générales pour le
mesurage de la température des grains entreposés en vrac dans
les installations de stockage
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus and system . 2
6 Procedure . 3
6.1 Positioning the measuring points .3
6.1.1 Grain temperature sensors .3
6.1.2 Warehouse temperature sensors .3
6.1.3 Air temperature sensors .3
6.2 Temperature readings .4
6.2.1 Frequency of readings .4
6.2.2 Particular requirements for ventilated warehouses .4
7 Temperature records . 4
7.1 General .4
7.2 Calibration .4
Annex A (informative) Temperature-reading devices . 5
Annex B (informative) Layout of temperature measuring points . 6

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
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The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
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This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 4, Cereals
and pulses.
This third edition cancels and replaces the second edition (ISO 4112:1990), which has been technically
revised.
The main changes are as follows:
— the term “warehouse” and its definition have been added;
— the apparatus for temperature measurement have been modified;
— the temperature sensors and thermometric system for stored grain have been added;
— the layout of temperature measurement points has been modified;
— the wireless communication technology and networking technology have been added;
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
Grain storage plays a crucial role in ensuring food security. The physiological processes which occur within
a mass of stored grain are accompanied by the emission of heat, and the external environmental factors
(e.g. hot climate, ventilation) can also cause grain temperature changes in bulk storage. As a result, the
temperature of the grain can reach a level at which serious permanent deterioration in the commercial,
technological and food properties of the grain will take place. It is therefore necessary to detect and measure
any overheating during storage and to take immediate remedial measures, such as ventilation and cooling,
since late remedial measures will, in most cases, have no effect.
In bulk storage, such damage is often in the initial stages, localized and affects only a small proportion of
the grain stored. However, such damage, although localized in the initial stages, can spread to other regions
of the stored grain if not checked in time, easily resulting in large-scale mildew contamination and pest
infestation. The consequences of any overheating, even if it is localized, are always serious since it is possible
that a batch of the grain will have to be marketed at reduced prices or can even become unsaleable because
of the presence of damaged grain. Because of the ever-increasing demand for grain of good quality and the
prolonged periods of bulk storage, it is important to check the temperature of the grain frequently. The use of
thermometric equipment, based on a large number of measuring points, is an appropriate technique to meet
this objective. On the other hand, manual temperature measurement is also an effective way to monitor the
health status of bulk grain in horizontal warehouses, even for long-term storage.
Thermometric equipment is also necessary to enable correct cooling by ventilation to be carried out. Such
cooling, using successive steps of 5 °C to 7 °C, can be economically employed in cold climates. At 0 °C, the
physiological activity of grain is insignificant even when its moisture content is close to the maximum
recognized internationally.
v
International Standard ISO 4112:2025(en)
Cereals and pulses — Guidance on measurement of the
temperature of grain stored in bulk
1 Scope
This document gives guidance on the measurement of the temperature of grain stored in bulk in storage
buildings, silos or any other warehouses, including detection apparatus, temperature sensors, layout of
temperature probes, digital display of results and measurement operation steps.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
grain
cereal grains and/or seeds of pulses
3.2
bulk storage
storage of grain (3.1) unpackaged in large quantities
Note 1 to entry: For example, in silo, squat silo and grain storage buildings.
3.3
warehouse
structure or building for grain storage with bas
...