How can I improve my numeric search?
Last updated on September 24, 2025
Compendex and Inspec records contain standardized numeric quantities and ranges. This normalized format of data improves numeric search functionality in Engineering Village.
Use the Expert search form to perform specific numeric searches in Compendex and Inspec.
You may also refine your numeric search results using the Numeric filter feature on the Quick and Expert search result pages. The Numeric filter is an easy way to construct a numeric search that does not require the use of field names and Boolean logic.
How
Follow the steps below to use Expert search syntax for numeric fields.
Refer to Numeric search fields for a detailed list of all fields available for numeric searches for both databases.
Construct your numeric search field queries using the components listed below in the following order:
- Field name (e.g., NU_TEMPERATURE, NU_CAPACITANCE)
- Operator (greater than [GT], greater than or equal to [GTE], less than [LT], less than or equal to [LTE], or equals [EQ])
- Numeric value
- Default unit (refer to Numeric search fields chart, e.g., "K", "W", "eV")
- Alternately, you may use the optional units of measure (e.g., lm/mm2, kW, MHz)
Note: It is not necessary to include the default or optional unit for the field in your numeric search query. However, if the default unit or optional unit is included in the search query, it is incorrect to use any other term other than the default or optional unit in the last component of the search query.
Search operators
See these examples below for valid greater than numeric search field queries:
Examples:
Find all Compendex documents with a temperature greater than 105 degrees Kelvin.
Since K is the default unit for the field NU_TEMPERATURE, it is not necessary to include the K in your numeric search query.
Valid User Queries | NU_TEMPERATURE GT 105 K |
| NU_TEMPERATURE GT 105 |
| NU_TEMPERATURE GT 1.05e+02 |
As the default unit for this field is K, using the term Kelvin or any default unit from any other field is incorrect.
Not Valid User Queries | NU_TEMPERATURE GT 10 Kelvin |
| NU_TEMPERATURE GT 10 Celsius |
| NU_TEMPERATURE GT 10 V |
| NU_TEMPERATURE GT 1.05e+02 m |
Refer to the examples below for valid greater than or equal to numeric search field queries.
It is possible that the results will be included within a numeric range.
Examples:
Find all Compendex documents with an electric field strength greater than or equal to 5 volts per meter.
Valid User Queries | NU_ELECTRIC_FIELD_STRENGTH GTE 5 V/m |
| NU_ELECTRIC_FIELD_STRENGTH GTE 5 |
| NU_ELECTRIC_FIELD_STRENGTH GTE 5.00e+00 |
Refer to the examples below for valid less than numeric search field queries.
Examples:
Find all Compendex and Inspec documents with a bit rate less than 50 bits per second.
Valid User Queries | NU_BIT_RATE LT 50 bit/s |
| NU_BIT_RATE LT 50 |
| NU_BIT_RATE LT 5.00e+01 |
Example:
Find all Compendex documents with the search term illuminance in any of the fields and an illuminance less than 5.00E+01 lumens per square millimeter.
This search query uses an optional unit of measure rather than a default unit. In order to ensure that all appropriate records are returned in your search results, it is advised to use the Numeric filter to easily search for records using the optional units.
Valid User Query | NU_ILLUMINANCE LT 5.00E+01 lm/mm2 AND (illuminance WN all) |
Less than or equal to (LTE)
Refer to the examples below for valid less than or equal to numeric search field queries.
It is possible that the results will be included within a numeric range.
Examples:
Find all Compendex documents with a capacitance less than or equal to 1.2 farad.
Valid User Queries | NU_CAPACITANCE LTE 1.2 F |
| NU_CAPACITANCE LTE 1.2 |
Refer to the examples below for valid equal to numeric search field queries.
It is possible that the results will be included within a numeric range.
Examples:
Find all Compendex documents with a specific surface area equal to 2 square meters per kilogram.
Valid User Queries | NU_SPECIFIC_SURFACE_AREA EQ 2 m2/Kg |
| NU_SPECIFIC_SURFACE_AREA EQ 2 |
Range operators
You may construct range searches using GTE and LTE operators in your search queries. Additionally, you may construct search queries that find records between two parameters within a range.
Refer to the examples below for range searches.
Examples:
Find all Compendex documents with power greater than or equal to 200 watts AND less than or equal to 400 watts.
Valid User Queries | NU_POWER GTE 200 W AND NU_POWER LTE 400 W |
| NU_POWER GTE 200 AND NU_POWER LTE 400 |
Find all Compendex documents with mass density less than or equal to 1,820 kilograms per cubic meter AND greater than or equal to 1,550 kilograms per cubic meter.
Valid User Queries | NU_MASS_DENSITY GTE 1.55e+03 kg/m3 AND NU_MASS_DENSITY LTE 1.82e+03 kg/m3 |
| NU_MASS_DENSITY GTE 1.55e+03 AND NU_MASS_DENSITY LTE 1.82e+03 |
Find all Inspec documents with a size between 0.055 mm AND 0.075 mm.
In the following example, identical default units (meter) are used in the search query.
The user needs to convert the millimeter numeric values to meters in order to construct this search query.
Valid User Queries | NU_SIZE GTE 5.50E-05 m AND NU_SIZE LTE 7.50E-05 m |
| NU_SIZE GTE 5.50E-05 AND NU_SIZE LTE 7.50E-05 |
Find all Compendex documents with a percentage between 6 AND 11%.
In the following example, there is no default unit listed for the first number in the range, but there is a default unit listed for the last number in the range.
Valid User Queries | NU_PERCENTAGE GTE 6 AND NU_PERCENTAGE LTE 11 % |
| NU_PERCENTAGE GTE 6.00e+00 AND NU_PERCENTAGE LTE 1.10e+01 % |
Find all Compendex documents with a frequency between 20 Hz AND 30 kHz.
In the following example, the default units are from different magnitudes (hertz and kilohertz).
The user needs to convert the kilohertz numeric value to hertz in order to construct this search query.
Valid User Queries | NU_FREQUENCY GTE 2.00e+01 Hz AND NU_FREQUENCY LTE 3.00e+04 Hz |
| NU_FREQUENCY GTE 2.00e+01 AND NU_FREQUENCY LTE 3.00e+04 |
You may combine different Boolean operators (AND, OR, NOT) within a numeric search query.
Refer to the examples below for Boolean searches within numeric search queries.
Examples:
Find all Compendex documents with greater than 200 joules AND greater than 4 kilograms per cubic meter.
Valid User Queries | NU_ENERGY GT 200 J AND NU_MASS_DENSITY GT 4 kg/m3 |
| NU_ENERGY GT 200 AND NU_MASS_DENSITY GT 4 |
| NU_ENERGY GT 2.00e+02 AND NU_MASS_DENSITY GT 4.0e+00 |
Find all Compendex documents with mass greater than 60 kilograms OR size greater than 2 meters.
Valid User Queries | NU_MASS GT 60 kg OR NU_SIZE GT 2 m |
| NU_MASS GT 60 OR NU_SIZE GT 2 |
| NU_MASS GT 6.00e+01 OR NU_SIZE GT 2.00e+00 |
Find all Inspec documents with magnetic flux density greater than 3.4 tesla NOT surface charge density less than 2.3 coulombs per square meter.
Valid User Queries | NU_MAGNETIC_FLUX_DENSITY GTE 3.4 T NOT NU_SURFACE_CHARGE_DENSITY LTE 2.3 C/m2 |
| NU_MAGNETIC_FLUX_DENSITY GTE 3.4 T NOT NU_SURFACE_CHARGE_DENSITY LTE 2.3 |
| NU_MAGNETIC_FLUX_DENSITY GTE 3.4 NOT NU_SURFACE_CHARGE_DENSITY LTE 2.3 C/m2 |
| NU_MAGNETIC_FLUX_DENSITY GTE 3.40e+00 T NOT NU_SURFACE_CHARGE_DENSITY LTE 2.30e+00 C/m2 |
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