DE2829931C2 - Portable gas measuring and warning device - Google Patents

Description

marked by

e) one between the output of the measuring circuit (4) and the input of the alarm device (10) switched threshold switch (6) to activate the alarm device (10) in the event if the output signal of the measuring circuit (4) exceeds the threshold value,

f) one with a power supply circuit (7) of the digital measured value display (5) in series the battery (1) placed thyristor (8), whose ignition electrode is connected to the output of the threshold switch (6) is connected,

g) an erase button (11) in series with the thyristor (8) in relation to the battery, as well as

h) a short-circuit button (9) placed parallel to the thyristor (8) and the delete button (11).

The invention relates to a portable gas measuring and warning device according to the preamble of the patent claim. Such a device is from a prospectus from Mine Safety Appliances Company, concerning the “Digital methane detector model Ν” (“Spotter”) from June 1978 known.

Such gas measuring and warning devices are used to monitor people or systems without direct access to the power grid and allow the early detection of explosive gas-air mixtures and warn the user with a visual and / or acoustic alarm.

It is known to carry out these tasks using portable devices with continuous monitoring and to be provided with permanent display of measured values and / or individual measurements. However, here it is as a Disadvantage to be seen that because of the constant display of measured values, an increased energy requirement for the battery-operated Gas measuring and warning devices is required

In a further known execution of a

A threshold value circuit is provided for the gas alarm device, which ignites a thyristor that activates an alarm lamp (Funk-Technik (1974) No. 13, p.

468-470).

The invention is based on the object of providing a portable gas measuring and warning device in question

ίο standing art to create and train so that the The energy requirement of the measured value display can be below the value customary in known devices

This object is achieved according to the invention by the measures specified in the characterizing part of the patent claim solved

The advantages achieved with the invention are in particular to limit the energy requirement for a digital output of measured values to the alarm case or the case of short-term measured value interrogation and thus to achieve a reduction in the energy requirement of a digital measured value display when used in battery-operated portable gas measuring and warning devices.
An exemplary embodiment is explained with reference to the drawing. The only figure in the drawing shows a block diagram of the portable gas measuring and warning device with digital display.

The operational sequence of the device is as follows:
After a switch 2 has been actuated, a battery 1 supplies a measuring arrangement 4 via a power supply 3. The output signal of the measuring arrangement 4 is simultaneously fed to a digital measured value display 5 and a threshold value switch 6 Thyristor 8, whereby a power supply 7 for the digital measured value display 5 is activated. At the same time, the output signal of the threshold switch 6 is fed to an optical and acoustic alarm unit 10. The gas concentration that is present is thus displayed even if the alarm threshold is undershot until it is acknowledged by pressing a button 11. Measured values lying below the alarm threshold of the threshold value switch 6 can be displayed by pressing a key 9. The digital display of measured values is carried out with LED displays.

1 sheet of drawings

Claims (1)

Claim: Portable gas measuring and warning device with a) a battery as a power source, b) a measuring circuit, c) a digital measured value display connected to the measuring circuit, as well as d) an alarm device