Oldham BM25 Operating Manual

17
Caution: measurements can be affected by high or low oxygen concentrations. Any reading
rapidly changing from too high (exceeding the scale) to too low can in fact indicate a
hazardous gas level higher than the measurement scale.
8.1. Display of instantaneous readings
8.1.1. Diffusion mode
All the instantaneous readings regarding gases are displayed in continuous mode.
The display unit is divided into four separate fields (quadrants).
Therefore, the operator can read:
• the measurement
• the measuring unit preceding the gas symbol
8.1.2. With electric pump systems
Caution: you must place a cover on the gas detector as indicated
• Wait a few seconds to read measurements. Any anomaly in the pump system is indicated
by an audible alarm and on the display unit
Caution: do not forget to remove the cover to return to diffusion mode.
8.1.3. With manual pump systems
Place the calibration pipe as shown
Wait for measurements to stabilize before recording them. They could be over-estimated (explosive
gas) or under-estimated (oxygen) during manual pumping due to air movement and system draining.
Caution: do not forget to remove the pipe to get back to diffusion mode.
8.2. Automatic range change « 0-100 % Gas »
With a explosimetric % LEL/ catharometric ( % vol) sensor and with an oxygene sensor
( mandatory in this case), the BM25 switches automatically from the gas explosibles measure range
“0-100% LEL” to the range “0-100% GAS” when the measure is above 100%LEL of the selected
gas reference.
Injection cover to be plug
ged to a
sampling kit (hose + probe).

Oldham BM25 Specifications

General

Brand	Oldham
Model	BM25
Category	Measuring Instruments
Language	English