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Alcohol Detection Systems vs Guardian

Your state's approved list decides first: in most states you can only choose from the companies on it. Where both are approved, the device, the service centers near you and the fees are what differ.

Alcohol Detection Systems logoAlcohol Detection SystemsDeterminator28 of 44 state lists
Guardian logoGuardianGuardian AMS 2500 (name from NM directory; site names no model)16 of 44 state lists

Where each one is approved

AlabamaAlaskaArizonaColoradoFloridaGeorgiaIndianaKansasMaineMassachusettsMinnesotaNew JerseyNorth CarolinaNorth DakotaOklahomaPennsylvaniaSouth DakotaTexasWyomingConnecticutMissouriWest VirginiaIllinoisNew MexicoArkansasCaliforniaDelawareDistrict of ColumbiaHawaiiIowaKentuckyMarylandMichiganMississippiMontanaNew HampshireNew YorkOhioOregonTennesseeUtahVirginiaWashingtonWisconsinNebraskaSouth CarolinaIdahoNevadaVermontLouisianaRhode Island
BothOnly Alcohol Detection SystemsOnly GuardianNeitherNo list we could read
Both 13

Arkansas, California, Georgia, Idaho, Indiana, Kentucky, Maryland, Massachusetts, Nebraska, New Jersey, Oklahoma, Rhode Island, Vermont

Only Alcohol Detection Systems 15

Alaska, Arizona, Connecticut, District of Columbia, Florida, Illinois, Kansas, Maine, Missouri, New Hampshire, Ohio, Oregon, Pennsylvania, South Carolina, Tennessee

Only Guardian 3

Colorado, Nevada, Texas

Alcohol Detection Systems vs Guardian: the devices

Alcohol Detection SystemsGuardian
How you blowThe Determinator 2 asks for a blow / suck / blow sample.1Not published
CameraThe Determinator 2 comes in a hand-held version with a camera.2Not published
Warm-upNo warm-up time is listed. The device must warm to operating temperature before it asks for a sample.3Guardian gives no warm-up figure. It says you may see a slightly longer warm-up during extreme cold.4
Rolling retest windowThe time you get to give a rolling retest sample is typically 3 minutes.5Not published
SensorNot publishedFuel cell. Guardian says the device uses fuel cell alcohol-specific technology.6
Operating temperatureNot publishedGuardian says accuracy exceeds NHTSA specifications of -40° to 180° F. This is a marketing claim.7
Size and weightNot publishedGuardian says the handset is similar in size and shape to a cell phone, and it is removable. No weight is given.8
MotorcyclesNot publishedGuardian says it does not install its device on motorcycles.9

Alcohol Detection Systems vs Guardian fees

FeeAlcohol Detection SystemsGuardian
Monthly leaseNot published$50-$120/monthNational10
InstallationNot published$0 total upfrontColorado, New Mexico and California only11
Enrollment or set-upNot published$0 total upfrontColorado, New Mexico and California only11

In Texas

Alcohol Detection SystemsGuardian
Certified service centers610
Advertisedby quote~$3/day
Installby quotefree

Texas DPS service center list; prices advertised Oct 23, 2026. Texas interlock guide

InterlockCompare is independent and isn't affiliated with either company. Not legal advice.

Sources 11 sources from 2 sites, including nmtsc.unm.edu, guardianinterlock.comShow

Every fact on this page comes from one of these.

  1. providing a Blow/Suck/Blow samplenmtsc.unm.edu/wp-content/uploads/ADS-User-Manual-Determinator-2.pdf
  2. Determinator Hand Held with Cameranmtsc.unm.edu/wp-content/uploads/ADS-User-Manual-Determinator-2.pdf
  3. The Determinator must warm to operating temperature before a sample is requestednmtsc.unm.edu/wp-content/uploads/ADS-User-Manual-Determinator-2.pdf
  4. you may see a slightly longer warm-up period during extreme coldguardianinterlock.com/support/faq
  5. The typical time allowed isnmtsc.unm.edu/wp-content/uploads/ADS-User-Manual-Determinator-2.pdf
  6. The Guardian IID features cutting-edge fuel cell alcohol-specific technologyguardianinterlock.com/guardian-ignition-interlock-device
  7. Accuracy exceeds NHTSA specifications (-40° to 180° F)guardianinterlock.com/guardian-ignition-interlock-device
  8. similar in size and shape to a cellular phoneguardianinterlock.com/support/faq
  9. No, we do not install our device on motorcyclesguardianinterlock.com/support/faq
  10. Leasing an ignition interlock device generally costs between $50-$120 per monthguardianinterlock.com/ignition-interlock-pricing
  11. Offer valid in Colorado, New Mexico, and California onlyguardianinterlock.com/ignition-interlock-pricing