Length Measurements

The laboratories of the length department are primarily concerned with maintaining the primary standard for the unit of length and disseminating traceability for dimensional measurements. Length measurements with high accuracy are of great importance in many applications, especially in military and industrial fields. The laboratories provide calibration services to factories and military and health and civil sectors at various levels to cover the basic needs of length and dimensional measurements that serve the Kingdom of Saudi Arabia. The length department divided into four laboratories: Wavelength Laboratory, Gauge Blocks Laboratory, Surface Measurements Laboratory, and Dimensions Laboratory.

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It is one of the length measurements department laboratories at the National Measurement and Calibration Center (NMCC). It is responsible for creating and maintaining the national standard for length unit (Metre), which is one of the seven basic units of measurement in the international system of units (SI). The laboratory provides the following calibration and measurement capabilities:

Calibration and Measurement Capabilities:

Calibration and Measurement Capability (CMC)، k=2 Range Quantity measured / Calibrated Instrument
20 kHz​
473 KHz​
Frequency stabilized Laser: absolute frequency
0.03 fm​
633 nm​
Frequency stabilized Laser: vacuum wavelength

Q[30; 0.27 L] nm,

L (mm)​

(0.5-100) mm

Short gauge block

(Interferometric method)

Q[49; 0.28 L] nm,

L (mm)

(125-1000) mm
​Long gauge block 

Q[88; 0.29 L] nm,

L (mm)

​​(125-1000) mm
Long gauge block

 

The Laboratory provides calibration services for gauge blocks by mechanical comparison method, angle block and surface plates calibration. The laboratory provides the following calibration and measurement capabilities:

Calibration and Measurement Capabilities:

Calibration and Measurement Cap​ability (CMC)، k=2 Range Quantity measured / Calibrated Instrument
30 nm
(0 – 10 ) mm

Gauge block comparators

Q [57، 0.4L] nm،

(L : mm)​


(0.5 – 100) mm

Gauge block: central length

0.05 µm
(0 – 0.5) mm

Gauge block: variation in length

0.4ʺ
​(0 - 90°)

Angle block

0.4ʺ
± 1000 arc seconds
Angel instruments level
Q[0.65; 1.7 L] mm, L(m)
(0 – 200) mm
Surface plate

The laboratory provides calibration services for the diameter standards, Form measurements and surface roughness measurement. The laboratory provides the following calibration and measurement capabilities:

Calibration and Measurement Capabilities:


Calibration and Measurement Capability (CMC)، k=2​ Range Quantity measured / Calibrated Instrument

Q [0.3; 0.004L] µm،

(L : mm)

(5 – 300) ​mm

Diameter of external cylinder (plug gauges) 

Q [0.3; 0.004L] µm،

(L : mm)​

(0.1 – 5) mm
Diameter of external cylinder (pin or wire)

Q [0.4; 0.004L]µm،

(L : mm)

(1.5 – 350) mm
Diameter of internal cylinder (ring،snap and gap gauge)

Q [0.3; 0.004L] µm،

(L : mm)

(1 – 300) mm
Diameter of sphere gauges
Q[60، 14R]،nm R in μm
​(0.01 – 300) µm
Roundness measurement 
Q[33، 13d]، nm d in μm
(0.01 – 50) µm
(Groove) depth standard (ISO 5436 - 1 Type A)، depth d
Q[12، 14Rz]nm ، Rz in μm
(0.01 – 50) µm
Roughness standard (ISO 5436-1 type D): ISO roughness parameters

The laboratory provides calibration services for several types of dimensional devices such as basic dimensional measuring devices, measuring tapes, and rulers. In addition, the Coordinate Measuring Machine (CMM) has multiple applications in the scope of dimensional measurement. The laboratory provides the following calibration and measurement capabilities:

Calibration and Measurement Capabilities:

Calibration and Measurement Capability (CMC)، k=2 Range​ Quantity measured / Calibrated Instrument

Q [80; 4.1L] mm,

(L : m)

(0 – 5000) mm
Steel tape and ruler

Q [0.5; 0.002L] mm,​

(L : mm)

(0 – 1000) mm
Step gauges

Q [0.5; 0.002L] mm,

(L : mm)

(2 – 100) mm
Diameter standards
3 mm
(5 – 700 ) mm
Screw Standards

Q [6; 0. 02L] mm,

(L : mm)

(0 – 1000) mm
Vernier Caliper
±0.001 mm
(0 – 100) mm
Outside Micrometer





Last modified 29 Jun 2021
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