Periodic checks are of utmost importance to ensure the proper state of operation due to the fact, that portable instruments are generally not used continuously. Those checks are described in the Instruction for Use of the individual instrument.
A distinction is drawn between field checking (response checking / bumptest), where no adjustment is made by the user and recalibrations, where adjustment is made when necessary.
Inspection and field checks are intended to verify that the device is in a good working state.
It is recommended, that this work is done by personnel using the instrument.
These checks shall be performed before carrying out safety relevant measurements.
If necessary (if the device fails the test), the device needs to be recalibrated.
We recommend the use of Dräger X-dock, our professional test- and calibration station, for this kind of procedures. It will perform the response checks of the devices in a very easy and fast way (8 -15 seconds, standard gases).
Additionally, the Dräger portable detection devices can be automatically recalibrated in case of failed accuracy tests by using the calibration mode of the Dräger X-dock.
General comment: The used test/calibration gas concentrations are recommended to be in the range of the selected alarm set points.
The most basic way to perform an accuracy check is by using a basic accuracy test set which consists of:
All gas detector devices need to be calibrated on a periodic basis as sensors may drift over a period of time and require adjustment.
Sensors may also experience drift after an over-exposure to the measurement gas, after an exposure to extreme environmental conditions, after a severe physical jolt, or if the accuracy check produces delivers a less than satisfactory result. An accuracy check is recommended prior to use to verify that the calibration is still valid.
The recommended standard calibration interval for Ex, O2, CO, H2S and CO2 is 6 months. Dräger understands that this cannot be performed in the Shipping industry for logistical reasons. The maximum calibration interval as required by Dräger for the standard Catalytic Ex sensor and the Electrochemical Oxygen-, Carbon Monoxide- and Hydrogen Sulphide sensors as well as our IR CO2 and IR Ex sensors, is once every twelve months. This is the maximum time between recalibrations that we confirm as allowable for these sensors with the understanding that an accuracy check (type: Extended Bumptest) is done prior to carrying out a safety-relevant measurement as described in the Dräger instruction for use.
The test type "Extended Bumptest" is a Bumptest that includes the check if gas is reaching the sensors and the alarm elements of the detector are triggered. More important is that it additionally checks that displayed gas concentration is within a pre-defined tolerance. Due to this unique specification it is - technically speaking - a calibration but without adjustment. This fact allows the extension of the interval. This Bumptest will fail if a detector will display values outside of the pre-defined tolerance. In this case the detector needs a full calibration.
The Photoionization sensor (PID) is special in respect of the recommended calibration interval. Best practice is a more frequent calibration of this sensor type because of potential environmental influences (temperature, humidity) and possible drift. Dräger recommends calibration of the PID sensor in the Dräger X-am 8000 latest every 30 days even if a longer calibration interval can be set in the instrument (with the help of the PC software CC Vision). This statement is also made in the Instruction for use of the instrument. With a less frequent use it is state of the art to perform a calibration before use in safety related applications. The calibration can be done by the user of the device via the instrument’s menu or with the support of the automatic test station Dräger X-dock using the certified Dräger Isobutylene calibration gas.
After 12 months the instrument needs official service, calibration and recertification at an authorized Dräger Service station.
|Plastic carrying case (blue) for 1 or 2 calibration gas cylinders (8 AL or 6D)||1||6811181|
Plastic carrying case (blue) for 1 or 2 calibration gas cylinders (8 AL or 6D)