Specifications

12
instruments developer at Geotechnical Instruments in England. Product information can be
found in Appendix 11 of this report.
Several WCB of BC lab tests were conducted prior to testing this new instrument in the field. A
sampling bag with 122 ppm N
2
O was sampled for a three hour period. Testing was also
conducted using a 25 ppm standard. The response time of the unit was verified by testing a 122
ppm standard for three 20 minute intervals. The machine was detached from the bag after 20
minutes and allowed to return to zero prior to re-connecting it. This machine has an accuracy of
+/- 10 ppm.
Other exposure and ventilation monitoring equipment included:
• Telog Instruments 2101Analog Voltage Recorder, Model # 2101-61 N/A 6499
• Foxboro Miran 203 Specific Vapour Analyzer Serial # 000060 with high efficiency
particulate filter 8F2B Serial # 40700853.
• Assay Technology Nitrous Oxide Badges, Lot # 2D01-4, Expiry Date 2/28/02, Item #
N575AT (see Appendix 9 for product information)
• Alnor Balometer Jr., s/n 3927
4.2.2 Procedure
Sampling was conducted between July 26 and August 2, 2001. Specific dates and times were as
follows:
Date Time
July 26 to July 27, 2001 7:30 am to 7:30 pm straight through
July 27, 2001 7:30 am to 7:30 pm
July 31 to August 2, 2001 7:30 am to 7:30 straight through
The industrial hygienist (researcher) lived at the hospital during the sampling times and the
nurses paged her to indicate that a woman was going to start using nitrous oxide.