Oldham MX 2100, Operating And Maintenance Manual

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If the selected gas is "Autre" (Other), a multiplying coefficient must be entered. (See Table 2).
Table 2 contains the coefficients for gases which do not have their coefficients entered in the appliance on a standard
basis.
These coefficients, to be programmed for the "Autres gaz" (Other gases) channel, are calculated with respect to
methane, as the appliance systematically recalculates the values of sensitivity coefficients with respect to that gas.
Table 2: Supplementary sensitivity coefficients to be programmed for the MX 2100 "other gases" channel
Gas Empirical
formula
LEL UEL Vapour
density Coefficient
/CH4
Benzene C6H6 1.2 % 8.0 % 2.7 2.2
Cyclohexanone (CH2)5CO 1.3 % 9.4 % 3.4 3.2
Premium petrol Mixture 1.3 % 6.0 % > 2 2.1
Ethane C2H6 3.0 % 15.5 % 1.04 1.0
LPG Prop+But 1.65 % ~9.0 % 1.85 1.48
Methylamine CH3NH2 4.9 % 20.7 % 1.1 1.05
Styrene C8H12 1.1 % 8.0 % 3.6 2.5
Octane > 2 3.0
Example of use:
Detection of white spirit with an MX 2100 appliance:
§
Select "Autre gaz" (Other gas) on the explosimetric channel.
§
Program the coefficient = 3.0.
§
Select the standard gas. If it is white spirit, select "Autre" (Other) as the standard gas.
§
Calibrate the appliance in the normal way, specifying the content for the standard gas used.
1.2. Cell calibration menu
This menu is used to regularly calibrate the cells connected to the appliance.
Calibration consists in adjusting the zero of the clean air cell (free of gas which may be detected by the MX 2100) and
adjusting sensitivity with a standard gas of known characteristics (including content, etc.).
1.3. Auto-zero menu
This menu lets you adjust the "zero" of each cell used in the MX 2100 automatically and simultaneously.
Caution: This menu must be used in clean air only.
1.4. Date and time management menu
This menu is used to update the internal calendar and clock of the MX 2100.
These data are used to define time scales, especially when the measurements stored in memory (min., max., STEL and
TWA) are printed out or downloaded to an external microcomputer.
Loss of date and time
The electronic circuits for the date and time are supplied with power by a specific lithium battery when the MX 2100 is
switched off. This battery has an estimated service life of 3 to 5 years. It must be replaced when that period of time has
passed, if the time -keeping is wrong or if the date cannot be stored in memory.
IMPORTANT: This operation is to be performed by OLDHAM or OLDHAM approved personnel only.