Michael Kenneth Wulff, petitioner, Appellant, vs. Commissioner of Public Safety, Respondent.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C4-98-862

Michael Kenneth Wulff, petitioner,

Appellant,

vs.

Commissioner of Public Safety,

Respondent.

 Filed November 17, 1998

 Affirmed

 Randall, Judge

Stevens County District Court

File No. C7-98-005

Stephen R. O'Brien, 426 Norwest Midland Building, Minneapolis, MN 55401 (for appellant)

Hubert H. Humphrey, III, Attorney General, Timothy C. Rank, Assistant Attorney General, 525 Park Street, Suite 200, St. Paul, MN 55103 (for respondent)

Considered and decided by Peterson, Presiding Judge, Randall, Judge, and Foley, Judge.[*]

 U N P U B L I S H E D O P I N I O N

 RANDALL, Judge

Appellant challenges the accuracy and reliability of an Intoxilyzer test, which resulted in the revocation of his driver's license. We affirm.

 FACTS

Appellant Michael Wulff was arrested on December 14, 1997, for driving while intoxicated. He was taken to the Morris police station, and the entire sequence of events after his arrival at the police station was recorded on videotape. The arresting officer, Deputy Jason Dingman, gave Wulff the implied consent advisory. After speaking by telephone with an attorney, Wulff agreed to take the Intoxilyzer test.

Officer Ross Tiegs, a certified Intoxilyzer operator, conducted the test. Wulff repeatedly did not produce a sufficient breath sample. Near the end of the four-minute time frame during which a breath sample can be provided, the Intoxilyzer indicated that there was radio frequency interference (RFI). Tiegs testified that he then asked Dingman if his radio was off and Dingman responded that it was off. Tiegs proceeded to administer a second Intoxilyzer test to Wulff. Wulff provided two adequate breath samples, which tested .148 (with a replicate value of .153) and .159 (with a replicate value of .160), resulting in a .14 reported value. The Intoxilyzer properly performed an internal diagnostic check, air blanks, and a calibration standard test during the second test, and the Intoxilyzer did not indicate RFI.

Wulff's driver's license was revoked, and the district court sustained that revocation after an implied consent hearing.

 D E C I S I O N

 I. District Court Findings

District court findings will be sustained unless they are clearly erroneous, and the district court's conclusions of law will not be reversed absent an erroneous view of the law. Fritzke v. Commissioner of Pub. Safety, 373 N.W.2d 649, 650 (Minn. App. 1985).

Wulff asserts that the following findings by the district court were clearly erroneous: (1) there were only two radios present while Tiegs performed the Intoxilyzer test; (2) Tiegs asked Dingman if his radio was on; (3) Dingman's radio was not on during the Intoxilyzer test; and (4) Dingman did not shut his radio off at 3:13 a.m. after the test had been administered. Wulff argues that the videotape contradicts the first three of these findings.

The videotape indicates that only Tiegs and Dingman were present with Wulff during the Intoxilyzer test. The tape does not demonstrate one way or the other whether there were two radios present during the test. There were two officers in the room, and Tiegs testified that there were only two portable radios in the room. We conclude the district court did not make a clearly erroneous finding that there were only two radios present during the test.

There is support for the district court's findings that Tiegs asked Dingman if his radio was off and that Dingman's radio was off during the test. Although Wulff insists that the videotape demonstrates that Tiegs never asked Dingman whether his radio was turned off, the tape shows Tiegs walk over to Dingman after the RFI indication and say something that is inaudible on the tape. In response, Dingman shakes his head side-to-side and reaches his hand down towards what appears to be his radio. Further, Tiegs testified that he asked Dingman about Dingman's radio at this point. Based on Tiegs's testimony and the actions shown on the videotape, the district court's findings that Tiegs asked about the radio and that the radio was off during the test were not clearly erroneous.

With regard to the finding that Dingman did not turn his radio off at 3:13 a.m. (after the test's completion), the videotape shows Dingman doing something with what appears to be his radio at 3:13 a.m. It is impossible to tell from the tape exactly what he is doing. Based on the district court's determination that Dingman had previously checked to see if his radio was on, and determined that it was not, the district court's finding that Dingman did not turn his radio off at 3:13 a.m. is not clearly erroneous.

 Trustworthiness

A chemical test's proponent must demonstrate that the test is reliable and that it was administered in conformance with the procedures necessary to ensure its reliability. State v. Dille, 258 N.W.2d 565, 567 (Minn. 1977). When a trained person conducts an Intoxilyzer test, the test results may be admitted without introduction of evidence that the machine "provides a trustworthy and reliable measure of alcohol in the breath." Ahrens v. Commissioner of Pub. Safety, 396 N.W.2d 653, 655 (Minn. App. 1986) (citation omitted); see also Minn. Stat. § 634.16 (1996) (stating same). The administration of the test is trustworthy when "there is a sufficient indicia of reliability or a showing of the steps necessary to ensure reliability." Ahrens, 396 N.W.2d at 655 (citations omitted). "The proponent does not have an absolute burden to show trustworthiness." Hager v. Commissioner of Pub. Safety, 382 N.W.2d 907, 909 (Minn. App. 1986) (citations omitted). Instead, once the proponent has made a prima facie showing of trustworthy administration, the burden is on the test's opponent to demonstrate the test's untrustworthiness. Id.

  A. Prima Facie Trustworthiness

Wulff argues that because the district court erred in its findings, the state has not established a prima facie case that the test was accurate and reliable. He argues that the videotape demonstrates that Tiegs did nothing to ensure the trustworthiness of the second test.

As stated above, the district court's findings were not erroneous. Further, the record does not demonstrate that the second test was inaccurate. During the second test, the Intoxilyzer performed an internal diagnostic check, air blanks, and a calibration standard test, and the Intoxilyzer registered a valid test. Importantly, the Intoxilyzer did not shut down or indicate RFI as it did during the first test.

  B. BCA Recommendations

Wulff also argues that because Tiegs failed to follow BCA recommendations, the test is invalid. The BCA recommends that if a test administrator receives an inhibited RFI indication, he should locate and remove the source or move the Intoxilyzer to another setting. Tiegs testified that he had been instructed by the BCA that if RFI is indicated during an Intoxilyzer test, the operator should try to determine the source of the interference.

We understand appellant's argument, and it is valid. Although technically BCA recommendations do not have the force of law and failure to follow them does not automatically make Intoxilyzer results invalid, Young v. Commissioner of Pub. Safety, 420 N.W.2d 585, 586 (Minn. 1988), this court stated:

We urge that BCA standards be strictly followed. That lessens the burden of a reviewing court which must determine the validity of the test. When the State's own recommended guidelines are not followed, the Commissioner's office bears the risk on appeal.

 Johnson v. Commissioner of Pub. Safety, 392 N.W.2d 359, 362 (Minn. App. 1986).

However, failure to follow a standard does not void a test per se. Rather, it depends on the importance of the standard at issue, coupled with the totality of the circumstances and the test. Wulff cites to McGregor v. Commissioner of Pub. Safety, 386 N.W.2d 339 (Minn. App. 1986), in support of his position that when BCA recommendations are not followed, the test is not trustworthy. In McGregor, the arresting police officer testified that although she observed the driver for 15 minutes prior to the Intoxilyzer test, she had no training and did not know the purpose of observation or what she should have been observing. Id. at 340. This court stated that "[u]nder the extreme facts" of that case, the commissioner did not meet his burden of establishing a prima facie showing of reliability. Id. at 341.

In contrast to McGregor, in this case Tiegs has been a certified Intoxilyzer operator since 1990. Despite being unable to recall the exact BCA instructions, Tiegs was aware of the BCA's general recommendations regarding RFI and knew that he should determine the source of the RFI. Although Tiegs did not locate the source of the disruption or move the Intoxilyzer, he did check to see if both of the radios in the room were off after the machine shut down. Further, the Intoxilyzer registered a valid second test. Unlike McGregor, this case does not involve "extreme facts." If there had been only one test, our analysis might be different. But here, since there was a valid second test with no indicia of interference, we conclude the district court did not err in refusing to find the second test invalid based on Tiegs's failure to follow all of the BCA recommendations.

  C. Petitioner's Burden to Rebut Prima Facie Trustworthiness

Wulff's final argument is that even if the state did make a prima facie showing of trustworthy administration, he presented sufficient evidence to establish that the test was invalid and unreliable. The district court concluded that Wulff failed to demonstrate that RFI was present during the second test and that even if he had met this burden, he did not show that the presence of RFI resulted in the Intoxilyzer registering a higher alcohol concentration than it would have if not for the presence of RFI. Wulff asserts that this conclusion is clearly erroneous and argues that the district court required him to meet an impossible burden of proof.

Although Wulff's expert testified that the test was unreliable because the RFI source had not been located, when asked whether he knew if RFI was present during the second test, he testified that no one knows whether RFI existed. Because there is no evidence that RFI actually existed during the second test, the district court did not err in concluding that Wulff failed to demonstrate that RFI was present during the second test. See Bond v. Commissioner of Pub. Safety, 570 N.W.2d 804, 807 (Minn. App. 1997) (stating "mere possibility" that Intoxilyzer simulator solution was used beyond its expiration date was not sufficient to rebut prima facie trustworthiness).

The district court also did not err in concluding that even if Wulff had proven the presence of RFI, Wulff did not present evidence that his Intoxilizer test result was higher than it would have been absent RFI. A person who challenges breath test results must demonstrate "that the perceived error results in a test showing a higher alcohol concentration than it would have but for the error." Schwarzrock v. Commissioner of Pub. Safety, 388 N.W.2d 425, 426 (Minn. App. 1986) (citations omitted). Wulff presented no evidence that the Intoxilyzer results would have been lower if RFI had not been present.

  Affirmed.

[*]Retired judge of the Minnesota Court of Appeals, serving as judge of the Minnesota Court of Appeals by appointment pursuant to Minn. Const. art. VI, § 10.