# Presentation: 346385

## LPG Liquid-Measuring DevicesPart 2: Inspection

- NIST Weights and Measures Division
- May 2005

## Inspection - Overview

- General Considerations
- Indicating/Recording Elements
- Measuring Elements
- Marking
- Piping

## Inspection

- Determine compliance with specs & other requirements (design, installation, operation)
- Not limited to _**visual**_ examination.....may need to _**verify**_ through test or other determination
- Extent & emphasis of inspection depends on:
- familiarity with the device
- age of device
- whether or not device NTEP approved
- whether or not complaint was received

## Indicating and Recording Elements - Analog vs. Digital Types

**analog type.  **A system of indication or recording** **in which values are presented as a series of graduations in combination with an indicator, or in which the most sensitive element of an indicating system _moves continuously_ during the operation of the device.
**digital type.  **A system of indication or recording of the selector type or one that _advances intermittently_ in which all values are presented digitally, or in numbers.  In a digital indicating or recording element, or in digital representation, there are no graduations.

## General Considerations – Selection

- Design and construction of device ensure accuracy and operation as intended
- Device must be suitable for application
- Volume Indications of sufficient capacity
- Flow rate
- Price computing capability is adequate
- Environment in which it is used
- Minimum delivery no less than 10 divisions for analog devices
- Minimum delivery no less than 100 divisions for other devices
- For example, 100 d on a 0.1 gal device is 10 gallons
- H44 Code References:  G-S.3., G-UR.1.1., G-UR.1.2., G-UR.1.3.

## General – Use and Maintenance

- Equipment operated in manner indicated by construction or instructions on equipment
- Some features may require instructions/markings
- Product/payment selectors, self-pay devices (key, card, cash)
- Owner required to maintain equipment in proper operating condition
- Owner cannot take advantage of tolerances
- Equipment cannot be in error predominantly in a direction favorable to owner (e.g., in “minus” direction)
- Also need to consider past history
- Some jurisdictions have specific policies to address this
- H44 Code References:  G-UR.3.1., G-UR.4.1., G-UR.4.2.

## General – Installation

- Installed according to manufacturer’s instructions
- Maximum discharge rate not in excess of rated maximum
- Performance not affected by installation
- Installed such that markings are readily observable
- No obstruction between primary elements and device
- Installation rigid and secure
- Device and associated equipment and installation do not facilitate fraud
- H44 Code References:  G-S.2., G-UR.2.1., G-UR.2.2., UR.1.1.

## General – Accessibility & Assistance

- Access
- Access to meters, printers, consoles, associated equipment
- Access to apply security seals & check audit trail info
- Access to device with your test equipment
- Access to electricity & product return
- Transportation to remote locations
- Devices brought to central location
- Assistance
- Operator for metering system
- Avoid liability for damage
- Some steps such as positioning prover may require 2 people
- H44 Code References:  G-UR.2.3., G-UR.4.4.

## General Considerations –Testing Devices at Central Location

- Devices which are routinely transported for the purpose of use (e.g., vehicle-mounted devices and devices used in multiple locations)
- Official may require devices to be brought to a central location for testing
- Dealer or owner shall provide transportation of the devices to and from the test location.
- H44 Code References:  G-UR.4.6.(a)

## Indicating and Recording Elements

- Design (S.1.1.)
- Device equipped with primary indicator
- Device _may_ be equipped with primary recording element
- Ticket Printer (UR.2.6.)
- Applies only in _**vehicle-mounted**_ applications
- Became retroactive 1/1/94
- applies to new _**and**_ existing installations
- Requires ticket printer
- Printer used for all sales
- Ticket must be left with customer
- H44 Code References:  S.1.1., UR.2.6.

## Indicating and Recording Elements - Design

- Value of Smallest Unit (S.1.1.3.)
- Shall not exceed:
- One pint on retail
- Note: 1 pint = 0.125 gallon
- One gallon on wholesale
- Minimizes effects of rounding on delivery size
- On analog device, smallest unit = smallest graduation on right-hand wheel
- On a digital device, the smallest unit is the smallest change in quantity that can be indicated
- H44 Code References:  S.1.1.3.

## Indicating and Recording Elements - Readability

- General (G-S.5.1.)
- Elements appropriate in design & adequate in amount
- Easy to read & understand in any condition of normal service
- Graduations, Indications, Recorded Representations (G-S.5.2.)
- Graduations and units uniform in size
- Subordinate values appropriately designated
- Values defined by words, symbols (e.g., gallons, liters, $)
- Graduations and defining figures not easily obliterated
- H44 Code Reference:  G-S.5.

## Indicating and Recording Elements 

- Not practical to check in field

- H44 Code Reference:  S.1.2, S.1.3

- S.1.2. Graduations.
- 	S.1.2.1. Length.
- 	S.1.2.2. Width.S.1.2.3. Clear Interval Between Graduations.
- S.1.3. Indicators.
- 	S.1.3.1. Symmetry.S.1.3.2. Length.
- 	S.1.3.3. Width.
- 	S.1.3.4. Clearance.
- 	S.1.3.5. Parallax.

## Indicating and Recording Elements - Readability

- Position of Equipment (G-UR.3.3.)
- Must be such that weighing or measuring operation can be observed . . .
- From some _**reasonable**_ customer positionand
- From some _**reasonable**_ operator position
- Use your judgment...put yourself in the customer’s and operator’s positions
- H44 Code Reference:  G-UR.3.3.

## Indicating and Recording Elements – Unit Price and Product Identity

- Unit price and product identity (S.1.5.1.)
- Stationary retail computing devices only
- Means to display on device:
- _unit price_
- _identity of product_ on each side
- _blend or grade_ (if able to dispense more than one grade or blend being dispensed)
- H44 Code Reference:  S.1.5.1.

## Indicating & Recording Elements – Advancement and Return to Zero

- Prevents manipulation prior to reaching zero
_*Advancement*_ only by mechanical operation of device
- _But_ can be cleared by advancing _only_ if:
- Once started, cannot stop until zero is reached or
- For indicating elements, elements are obscured until zero is reached
- e.g., shutters, analog, blanking, etc.
- Primary indicating elements and recording elements, when these are returnable to zero, shall be returned to zero before each delivery.
- H44 Code Reference:  S.1.1.4., S.1.4.1., S.1.4.2., S.1.6.1.

## Indicating and Recording Elements – Provision for Sealing

- Provision for Sealing, Electronic (G-S.8., 1/1/90)
- Requires device to be designed with provision to apply security seal
- Physical seal or other approved means (e.g., audit trail)
- Seal protects against metrological changes
- Security Seal (G-UR.4.5.)
- Security seal must be affixed to adjustment mechanism designed to be sealed

## Measuring Elements – Vapor Elimination

- Vapor Elimination (S.2.1.)
- Device shall be equipped with an effective vapor eliminator or other effective means to prevent the passage of vapor through the meter
- Maintenance of Liquid State (S.2.4.)
- Device shall be so designed and installed that the product being measured will remain in a liquid state during the passage through the meter

## Measuring Elements – Security Seals

- Provision for Sealing (S.2.2.)
- Provision for approved means of security on:
- Measurement element
- Adjustable element for controlling delivery rates when rates affect accuracy
- Adjusting mechanism readily accessible
- Audit trails as specified in LMD Code Table S.2.2.
- Automatic Temperature Compensator (ATC) (S.2.6.2.)
- Provision made for sealing ATC to prevent deactivation
- Handbook 44 Code References:  G‐UR.4.5., S.2.2., S.2.6.2.

## Provision for Sealing – Table S.2.2. (1/1/95)

- Category 1:
- No remote configuration
**Sealing:**
- Physical seal or two event counters
- Category 2:
- Remote configuration, but access controlled by hardware
- Only for devices manufactured prior to 1/1/05
**Sealing:**
- Physical seal on hardware _**or**_ two event counters
- Clear indication when in calibration mode
- If counters are at system controller, means to generate hard copy of information through on-site device (1/1/96)

## Provision for Sealing – Table S.2.2. (1/1/95)

- Category 3:
- Remote configuration, access unlimited or controlled through software switch
**Sealing:**
- Event logger required
- Clear indication when in calibration mode (1/1/01)
- Printed copy of information available through device or another on-site device
- Note:  As of 2005, all devices with remote configuration must meet Category 3.

## Measuring Elements

- Thermometer well (S.2.5.)
- Means shall be provided to determine the temperature of the liquid either:
- in the liquid chamber of the meter, or
- in the meter inlet or discharge line and immediately adjacent to the meter.
- Automatic temperature compensation (S.2.6., UR.2.4.)
- Device _may_ be equipped with automatic temperature compensator (S.2.6.)
- NIST Handbook 130 _requires_ ATC on meters with greater than 20 gpm rated maximum
- Provision must be provided for deactivating (S.2.6.1.)
- Compensator in use and activated at all times (UR.2.4.)
- May only be deactivated with permission from W&M

## Marking

- Devices marked clearly and permanently
- Riveted metal badge or pressure-sensitive material
- Markings required:
- Mfg/distributor name
- Model
- Preface identifying model number (NR 1/1/03)
- Serial number (NR 1/1/68) (except software-based devices)
- Software version, on not-built-for purpose software-based (1/1/04)
- Preface identifying serial number (NR 1/1/86)
- NTEP Certificate of Conformance Number, if applicable (NR 1/1/03)
- Remanufacturer information on remanufactured devices (1/1/02)
- H44 Code References:  G-S.1., G-S.1.1. (1/1/04), G-S.1.2. (1/1/02), G-UR.2.1.1., G-UR.3.4.

## Marking

- G-S.6. Marking Operational Controls, Indications, Features (NR 1/1/77)
- Controls, features clearly identified
- Pictograms acceptable
- G-S.7. Lettering
- Required markings distinct & easy to read
- Not easily obliterated

## Marking

- Limitation of Use (S.4.1.)
- If device designed to operate with only specific liquids, must be marked accordingly
- Discharge Rate (S.4.2.)
- Minimum and maximum flow rates must be marked
- Minimum not greater than 5 gpm for stationary retail
- Minimum not greater than 20% of maximum for all other devices
- Temperature Compensated (S.4.3.)
- Device with ATC must be marked to show indications are corrected to 60 degrees F
- Printed indications must also be marked

## Piping – Discharge Line and Valves

- Directional Flow Valve (S‐2.3.)
- Valve or other automatic means provided to prevent reversal of flow
- Diversion of Measured Liquid (S.3.1.)
- No means for diverting measured liquid
- Two delivery outlets permitted, provided:
- Liquid can only flow from one outlet at a time, and
- Direction of flow clearly indicated
- Manually-controlled outlet for service permitted, but must have provision for sealing

## Piping – Discharge Line and Valves

- Delivery hose (S.3.2.)
- “Wet-hose” type, full of product at all times
- Shut off at outlet end
- Length of Discharge Hose (UR.1.2.)
- No greater than 18 ft for stationary retail devices
- Exceptions made if need can be demonstrated
- Condition of Discharge Hose (UR.2.2.)
- Must be completely filled with liquid before “zero”
- Facilitation of fraud (G-S.2)
- Equipment of design so as not to facilitate fraud

## Piping – Discharge Line and Valves

- Vapor Return Line (UR.2.3.)
- No vapor return line permitted between metering system and receiving tank during metered delivery
- Vapor in the receiving tank belongs to customer
- Spray fill tank design enables efficient delivery
- Promotes condensation and reduces pressure
- Used in testing -- allows vapor initially in prover to be pushed back into system tank
- If vapor in prover were to remain, pressure from incoming liquid would cause condensation
- Necessary for testing; not possible to determine amount of product resulting from vapor condensation
- Reduces pressure

## Part 1: Inspection- Summary

**Indicating/Recording Elements**
- Design
- Readability
- Ticket Printer (Vehicle-Mounted)
- Unit Price & Product Identity
- Advancement & Return to Zero
- Provision for Sealing
**Measuring Elements**
- Vapor Elimination
- Security Seals
- Thermometer Well
- Automatic Temperature Compensation

## Part 1: Inspection- Summary (cont.)

**Marking**
**Piping**
- Discharge Line & Valves
- Facilitation of Fraud
**General Considerations**
- Selection
- Use & Maintenance
- Installation
- Accessibility
- Assistance
- Testing Devices at a Central Location