Date: 201603
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Fuel Quantity-Pressure Indication
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; Captain
Anomaly: ATC Issue All Types; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Procedure; Human Factors; Aircraft
Primary problem: Ambiguous

Narrative: This was the third leg of the day for us. The fuel status at the before start checklist was either 4.5 or 4.6 on board and 4.7 was required so we were within our +/- 300 lbs. limits and over the 3.8 required for takeoff fuel. We pushed back 2 minutes early. We had been given a wheels up time from ground control so we single engine taxied to the hold short line. We waited to start the second engine; which was perfect timing because we were given the takeoff clearance almost right away after it was started. The before takeoff checklist fuel was about 4.2 or 4.3 on board and 3.8 was required. The takeoff and climb were routine and we were not vectored unusually long on the initial climb out. The captain was flying this leg. I think there was some speed restrictions during cruise that may have put us slightly behind schedule and I noticed the captain flying around 300 knots to try to get us back on time. I did notice he was updating the FMS with the speed changes and keeping a good watch on the fuel status (as he had done on the other legs we had flown together so far). We were also stopped at FL250 for a final altitude instead of the FL270 that was planned; which would have a small effect on the fuel consumption. During our arrival ATC directed us to a heading of 180 and told us to expect holding. The frequency was busy and no reason or time frame was given initially. A few minutes later we were told to expect holding for about 10 minutes. Captain told me to declare Min Fuel with ATC and also told ATC that we had no alternate/hold fuel. ATC then asked us where we would like to go. I saw that we were at about 1500 lbs EFOA (Expected Fuel On Arrival) but heading away from our destination. Captain then sent dispatch messages asking about diversion. The first thing suggested was ZZZ1; which was no good because it was even further away. We suggested ZZZ2 because it would be in front of us on the 180 heading. Dispatcher just sent us weather for ZZZ2 with no real yes or no advising. During those communications; ATC then advised us that we could be cleared to our destination via the arrival at 210 knots. We accepted that and captain updated the FMS again and it showed about 1300 lbs EFOA by the time we were established on the arrival again. This was well below our reserves.ATC asked us what we wanted and we advised ATC that we wanted direct to the airport. ATC cleared us direct to the airport and captain delayed configuring a little longer than usual to reduce any extra fuel spent due to the extra drag. We landed safely and taxied to the parking spot. We were clocked in with 1210 lbs. of fuel on board. I felt the captain handled the situation well and was never uncomfortable with the way the situation unfolded. I did notice on the next flight in this aircraft that the fuel was also 100 to 200 lbs. less than ramp fuel by the time of the before start checklist. I do not remember the fuel on the first two legs; but might be related to some sort of possible fuel sensor problem on the aircraft.


Second narrative: [Report narrative contained no additional information.]


Synopsis: Air carrier flight crew reported experiencing delays to their destination resulting in a low fuel state.