Air cleaner clogging indicators ИЗВ-500, ИЗВ-600, ИЗВ-700 | PAO Saransk Instrument Works

Air cleaner clogging indicators ИЗВ-500, ИЗВ-600, ИЗВ-700

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Паспорт ИЗВ-500, ИЗВ-600, ИЗВ-700

Air cleaner clogging indicators (engine air filter clogging sensor) ИЗВ-500, ИЗВ-600, ИЗВ-700 are designed to monitor clogging of air cleaners in engines of heavy duty vehicles, tractors, and agricultural machinery.

Design and operating principle


1. Air cleaner clogging indicators use a red drum (signal position) as a signaling device. There is a knurled disc on the top of the indicator designed to turn the drum into operating position. The disc is turned in the direction indicated by the pointer until it stops and then released.

The drum remains fixed in this position and automatically moves to signal position when the maximum allowable clogging of the air cleaner is reached. At the same time, red paint appears in the indicator housing windows, which means that the air cleaner requires maintenance. After maintenance, it is necessary to reset the indicator drum to operating position. 

Indicator preparation for operation

1. Air cleaner clogging indicators can be installed directly in the line of purified air between the air cleaner and the engine, and also in the driver’s cabin – upon its attachment to the purified air line using a leak-tight pipeline, withstanding the vacuum up to 10 kPa.

2. Prior to installation, it is necessary to eliminate the wire from the mounting nozzle hole that protects this hole against clogging. Turn the knurled disc to the direction indicated by the arrow in order to set the drum to operating position.

3. It is allowed to remove the air cleaner clogging indicator in the course of operation together with rubber mounting sleeve, using which it is connected to the mounting nozzle. In this case, prior to installation of the indicator to its place, it is required to extract the sleeve from it, put in to the nozzle so, that the top end goes behind the nozzle side, then set the indicator to the sleeve. To facilitate the installation, it is allowed to lubricate the sealing bands of the sleeve with a thin layer of grease.

General specifications

Limit of measured vacuum at which the signal is followed by the air cleaner clogging indicator, kPa:







Operating position of air cleaner clogging indicators is vertical, with a deflection angle up to 30°. –page 65 of the Catalog

Ambient medium parameters:

- temperature, °С


- relative humidity at temperature of 35°С, %


Clogging indicator weight, kg, as maximum


Overall dimensions of clogging indicators, mm



When ordering, it is required to specify the following:

  1. Description of air cleaner clogging indicator
  2. Designation
  3. Connecting nozzle version: threaded or for elastic tubing
  4. ТУ designation

Example of an order

Clogging indicator with a measuring limit of 7 kPa, connecting nozzle threaded as per GOST 6111-52, climatic version У2:

“Air cleaner clogging indicator ИЗВ-700, threaded nozzle, ТУ 25.02-1749-75”.


 Clogging indicator with a measuring limit of 5 kPa, connecting nozzle for tubing, climatic version У2, supplied for export:


“Air cleaner clogging indicator ИЗВ-500-У2, elastic tubing, ТУ 25.02.1749 78”. Overall and attachment dimensions

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